Camptothecin Analogs, Conjugates, and Methods of Use

Abstract

Camptothecin analogs of formula (I) and conjugates containing the camptothecin analogs are described. The camptothecin analogs and conjugates can be used as therapeutic agents, particularly in the treatment of cancer, autoimmune diseases or viral infections. TIFF2024519140000363.tif42164

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to the field of therapeutic agents, and in particular to camptothecin analogs, conjugates containing camptothecin analogs, and their use in therapy. [Background technology]

[0002] Camptothecin is a natural product that inhibits topoisomerase I and has broad-spectrum antitumor activity. However, camptothecin is poorly soluble, making it unsuitable for clinical development. Therefore, considerable effort has been directed toward identifying camptothecin analogs or derivatives with properties more suitable for therapeutic use. Two derivatives, irinotecan and topotecan, have been approved for the treatment of cancer. Irinotecan is a prodrug that is converted in vivo to a more potent analog, SN-38. A third derivative, belotecan, has been approved in South Korea.

[0003] Camptothecin analogs have also been developed as payloads for antibody-drug conjugates (ADCs). Two such ADCs have been approved for the treatment of cancer: trastuzumab deruxtecan (Enhertu™), in which the camptothecin analog deruxtecan (Dxd) is conjugated to the anti-HER2 antibody trastuzumab via a cleavable tetrapeptide-based linker, and sacituzumab govitecan (Trodelvy™), in which the camptothecin analog SN-38 is conjugated to the anti-Trop-2 antibody sacituzumab via a hydrolyzable, pH-sensitive linker.

[0004] Other camptothecin analogs and derivatives, and ADCs containing them, have been described (see, e.g., International (PCT) Publication Nos. WO2019 / 195665; WO2019 / 236954; WO2020 / 200880; and WO2020 / 219287).

[0005] This background information is provided for the purpose of making known information believed by the applicant to be of possible relevance to the present disclosure. No admission is necessarily intended, nor should it be construed, that any of the preceding information constitutes prior art against the claimed invention. Summary of the Invention

[0006] Described herein are camptothecin analog compounds, conjugates comprising the compounds, and methods of treatment using the compounds and conjugates. In one aspect, the disclosure provides camptothecin analog compounds of formula (I): [ka] A compound having the formula: R 1 is selected from —H, —CH3, —CHF2, —CF3, —F, —Br, —Cl, —OH, —OCH3, —OCF3, and —NH2; R 2 is selected from —H, —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3, and —OCF3; R 1 is -NH2, R is R 3 or R 4 and R 1 is other than -NH2, R is R 4 and R 3 is -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , [ka] -CO2R 8 , -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; R 4 teeth, [ka] is selected from R 5is selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, -aryl, and -(C1-C6 alkyl)-aryl; R 6 and R 7 are each independently -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , —C3-C8 heterocycloalkyl and —C(O)R 17 is selected from R 8 is selected from —H, —C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; Each R 9 are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; Each R 10 are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; R 10’ is selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 11 is selected from —H and —C1-C6 alkyl; R 12 is -H, -C1-C6 alkyl, -CO2R 8 , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, -S(O)2R 16 and [ka] is selected from R 13 is selected from —H and —C1-C6 alkyl; R 14 and R 14’are each independently selected from —H, C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; R 16 is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 17 is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -C3-C8 heterocycloalkyl, -(C1-C6 alkyl)-C3-C8 heterocycloalkyl, -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; R 18 and R 19 together with the N atom to which they are attached, include halogen, -C1-C6 alkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5 forming a 4-, 5-, 6- or 7-membered ring having 0 to 3 substituents selected from R 24 , R 25 and R 26 are each -C1 to C6 alkyl, X a and X b are each independently selected from NH, O, and S; X c is selected from O, S and S(O)2; However, the compound is other than (S)-9-amino-11-butyl-4-ethyl-4-hydroxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione.

[0007] In certain embodiments, in compounds of formula (I), R 1 is NH2 and R 2 is other than -H.

[0008] Another aspect of the present disclosure relates to a pharmaceutical composition comprising a compound having formula (I) and a pharmaceutically acceptable carrier or diluent.

[0009] Another aspect of the present disclosure relates to a method for inhibiting the proliferation of cancer cells, comprising contacting the cells with an effective amount of a compound having formula (I). Another aspect relates to a method for killing cancer cells, comprising contacting the cells with an effective amount of a compound having formula (I).

[0010] Another aspect of the present disclosure relates to a method of treating cancer in a subject in need thereof, comprising administering to the subject an effective amount of a compound having Formula (I). Another aspect relates to a method of treating an autoimmune disease in a subject in need thereof, comprising administering to the subject an effective amount of a compound having Formula (I). Another aspect relates to a method of treating a viral infection in a subject in need thereof, comprising administering to the subject an effective amount of a compound having Formula (I).

[0011] Another aspect of the present disclosure relates to a compound having formula (I) for use in therapy. Another aspect relates to a compound of formula (I) for use in the treatment of cancer, an autoimmune disease, or a viral infection.

[0012] Another aspect of the present disclosure relates to the use of a compound having formula (I) in the manufacture of a medicament for the treatment of cancer, an autoimmune disease, or a viral infection.

[0013] Another aspect of the present disclosure is a compound of formula (X): T-[L-(D) m ] n (X) A complex having the formula: T is a targeting moiety, L is a linker, D is a camptothecin analog described herein; m is an integer between 1 and 4, n is an integer between 1 and 10 for the complex.

[0014] Another aspect of the present disclosure is a compound of formula (X): T-[L-(D) m ] n (X) A complex having the formula: T is a targeting moiety, L is a linker, m is an integer between 1 and 4, n is an integer between 1 and 10, D is a compound of formula (IV): [ka] is a compound of the formula R 1a is selected from —H, —CH3, —CHF2, —CF3, —F, —Br, —Cl, —OH, —OCH3, —OCF3, and —NH2; R 2a is selected from —H, —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3, and —OCF3; X is -O-, -S- or -NH-, and R 4a teeth, [ka] wherein * is the point of attachment to X and p is 1, 2, 3 or 4; or X is O and R 4a -X- is [ka] is selected from R 5a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 8a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl; Each R 9aare independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; or R 9a does not exist, X b =X, Each R 10a are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, and [ka] is selected from Each R 10a’ are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; Each R 10b are independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 11a is absent or is -C1-C6 alkyl, R 12a is -C1 to C6 alkyl, -CO2R 8a , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, -S(O)2R 16a and [ka] is selected from R 13a is selected from —H and —C1-C6 alkyl; R 14a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl; R 14a’ is selected from H, —C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; R 16ais selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 21 is -C1-C6 alkyl, -C3-C8 cycloalkyl and -(C1-C6 alkyl)-OR 5a is selected from R 22 and R 23 are each independently selected from -H, -halogen, C1-C6 alkyl, and -C3-C8 cycloalkyl; R 24 , R 25 and R 26 are each -C1 to C6 alkyl, X a and X b are each independently selected from NH, O, and S; X c is selected from O, S and S(O)2; [ka] refers to the conjugate, indicating the point of attachment to the linker L.

[0015] Another aspect of the present disclosure is a compound of formula (X): T-[L-(D) m ] n (X) A complex having the formula: T is a targeting moiety, L is a linker, m is an integer between 1 and 4, n is an integer between 1 and 10, D is a compound of formula (V): [ka] is a compound of the formula R 2a is selected from —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3 and —OCF3; R 20ais -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , [ka] -CO2R 8 , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, [ka] is selected from R 5 is selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 6 and R 7 are each independently -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , —C3-C8 heterocycloalkyl and —C(O)R 17 is selected from R 8 is selected from —H, —C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; Each R 9 are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; Each R 10a are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, and [ka] is selected from R 10a’ is selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 11is selected from —H and —C1-C6 alkyl; R 12 is -H, -C1-C6 alkyl, -CO2R 8 , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, -S(O)2R 16 and [ka] is selected from R 13 is selected from —H and —C1-C6 alkyl; R 14 and R 14’ are each independently selected from —H, C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; R 16 is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 17 is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -C3-C8 heterocycloalkyl, -(C1-C6 alkyl)-C3-C8 heterocycloalkyl, -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; R 18 and R 19 together with the N atom to which they are attached, include halogen, -C1-C6 alkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5 forming a 4-, 5-, 6- or 7-membered ring having 0 to 3 substituents selected from R 24 , R 25 and R 26 are each -C1 to C6 alkyl, X a and X b are each independently selected from NH, O, and S; X c is selected from O, S and S(O)2; [ka] refers to the conjugate, indicating the point of attachment to the linker L.

[0016] Another aspect of the present disclosure is a compound of formula (X): T-[L-(D) m ] n (X) A complex having the formula: T is a targeting moiety, L is a linker, m is an integer between 1 and 4, n is an integer between 1 and 10, D is a compound of formula (VI): [ka] is a compound of the formula R 2a is selected from —H, —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3, and —OCF3; X is -O-, -S- or -NH-, and R 25 is -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5a , -CO2R 8a , —C(O)—, -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, [ka] wherein * is the point of attachment to X and p is 1, 2, 3 or 4; or X is O and R 25 -X- is [ka] is selected from R 5a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 6ais selected from —H, —C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; R 7a is -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5a , —C3-C8 heterocycloalkyl and —C(O)R 17a is selected from R 8a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl; Each R 9a are independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; or R 9a does not exist, X b =X, Each R 10a are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, and [ka] is selected from Each R 10a’ are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; Each R 10b are independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 11a is absent or is -C1-C6 alkyl, R 12a is -C1 to C6 alkyl, -CO2R 8a , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, -S(O)2R 16a and [ka] is selected from R 13a is selected from —H and —C1-C6 alkyl; R 14a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl; R 14a’ is selected from H, —C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; R 16a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 17a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -C3-C8 heterocycloalkyl, -(C1-C6 alkyl)-C3-C8 heterocycloalkyl, -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; R 21 is -C1-C6 alkyl, -C3-C8 cycloalkyl and -(C1-C6 alkyl)-OR 5a is selected from R 22 and R 23 are each independently selected from -H, -halogen, C1-C6 alkyl, and -C3-C8 cycloalkyl; R 24 , R 25 and R 26 are each -C1 to C6 alkyl, X a and X b are each independently selected from NH, O, and S; X c is selected from O, S and S(O)2; [ka] refers to the conjugate, indicating the point of attachment to the linker L.

[0017] Another aspect of the present disclosure relates to a pharmaceutical composition comprising a conjugate of formula (X) and a pharmaceutically acceptable carrier or diluent.

[0018] Another aspect of the present disclosure relates to a method for inhibiting the proliferation of cancer cells, comprising contacting the cells with an effective amount of a conjugate having formula (X). Another aspect relates to a method for killing cancer cells, comprising contacting the cells with an effective amount of a conjugate having formula (X).

[0019] Another aspect of the present disclosure relates to a method of treating cancer in a subject in need thereof, comprising administering to the subject an effective amount of a conjugate of Formula (X). Another aspect relates to a method of treating an autoimmune disease in a subject in need thereof, comprising administering to the subject an effective amount of a conjugate of Formula (X). Another aspect relates to a method of treating a viral infection in a subject in need thereof, comprising administering to the subject an effective amount of a conjugate of Formula (X).

[0020] Another aspect of the present disclosure relates to a conjugate having formula (X) for use in therapy. Another aspect relates to a conjugate having formula (X) for use in the treatment of cancer, autoimmune disease, or viral infection.

[0021] Another aspect of the present disclosure relates to the use of a conjugate having Formula (X) in the manufacture of a medicament for the treatment of cancer, an autoimmune disease, or a viral infection. [Brief explanation of the drawings]

[0022] [Figure 1A] 1 shows a schematic representation of general procedures that can be used to prepare intermediates for the synthesis of camptothecin analogs and conjugates described herein. Synthetic Scheme I: General Procedure 1. [Figure 1B]

[0033] Figure 1 shows a schematic representation of a general procedure that can be used to prepare intermediates for the synthesis of camptothecin analogs and conjugates described herein. Synthetic Scheme II: General Procedure 2 [Figure 1C]1 shows a schematic representation of general procedures that can be used to prepare intermediates for the synthesis of camptothecin analogs and conjugates described herein. Synthetic Scheme III: General Procedure 3. [Figure 1D] 1 shows a schematic representation of general procedures that can be used to prepare intermediates for the synthesis of camptothecin analogs and conjugates described herein. Synthetic Scheme IV: General Procedure 4. [Figure 1E] 1 shows a schematic representation of general procedures that can be used to prepare intermediates for the synthesis of camptothecin analogs and conjugates described herein. Synthetic Scheme V: General Procedure 5. [Figure 1F] 1 shows a schematic representation of a general procedure that can be used to prepare intermediates for the synthesis of camptothecin analogs and conjugates described herein.Synthetic Scheme VI: General Procedure 7. [Figure 1G] 1 shows a schematic representation of a general procedure that can be used to prepare intermediates for the synthesis of camptothecin analogs and conjugates described herein. Synthetic Scheme VII: General Procedure 8.

[0023] [Figure 2A] 1 shows the bystander killing effect of a conjugate comprising a camptothecin analog described herein conjugated to trastuzumab at a DAR of 1 nM concentration on HER2-negative MDA-MB-468 cancer cells. [Figure 2B] 1 shows the bystander killing effect of a conjugate comprising a camptothecin analog described herein conjugated to trastuzumab at a DAR of 0.1 nM concentration on HER2-negative MDA-MB-468 cancer cells.

[0024] [Figure 3] 1 shows the antitumor activity of a conjugate comprising a camptothecin analog described herein conjugated to trastuzumab at DAR8 in the JIMT-1 xenograft model of HER2-expressing (intermediate) breast cancer.

[0025] [Figure 4] Exemplary drug-linker (DL) structures containing camptothecin analogs of formula (I) with a C7 linkage are shown (Table 4).

[0026] [Figure 5] Exemplary drug-linker (DL) structures containing camptothecin analogs of formula (I) with a C10 bond are shown (Table 5).

[0027] [Figure 6] Exemplary drug-linker (DL) structures are shown (Table 6), including camptothecin analogs of formula (I) with C7 or C10 linkages.

[0028] [Figure 7] Exemplary complex (DC) structures containing camptothecin analogs of formula (I) with a C7 linkage are shown (Table 7).

[0029] [Figure 8] Exemplary conjugate (DC) structures containing camptothecin analogs of formula (I) with a C10 linkage are shown (Table 8).

[0030] [Figure 9] Exemplary complex (DC) structures containing camptothecin analogs of formula (I) with C7 or C10 linkages are shown (Table 9).

[0031] [Figure 10A] 1 shows the in vivo anti-tumor activity in an OV90 xenograft model of anti-FRα antibody v30384 conjugated with camptothecin analogs, Compound 139 and Compound 141, at DAR8. [Figure 10B] 1 shows the in vivo anti-tumor activity in an OV90 xenograft model of anti-FRα antibody v30384 conjugated with camptothecin analogs, Compound 140 and Compound 141, at DAR8. [Figure 10C] 1 shows the in vivo anti-tumor activity in the H2110 xenograft model of anti-FRα antibody v30384 conjugated with camptothecin analogs, Compound 139, Compound 140, Compound 141, and Compound 148, at DAR8. DETAILED DESCRIPTION OF THE INVENTION

[0032] The present disclosure relates to camptothecin analogs and conjugates containing camptothecin analogs. Camptothecin analogs and conjugates have been shown to have cytotoxic activity, for example, against cancer cells. Accordingly, certain embodiments of the present disclosure relate to the use of camptothecin analogs and conjugates as therapeutic agents, particularly in the treatment of cancer.

[0033] definition Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0034] As used herein, the term "about" refers to approximately a ±10% variation from a given value. It is to be understood that such a variation is always included in any given value provided herein, whether or not it is specifically referred to.

[0035] The use of the words "a" or "an," when used herein in conjunction with the term "comprising," can mean "one," but is also consistent with the meaning of "one or more," "at least one," and "one or more than one."

[0036] As used herein, the terms "comprising," "having," "including," and "containing," as well as grammatical variations thereof, are inclusive, i.e., open-ended, and do not exclude additional, unrecited elements and / or method steps. The term "consisting essentially of," when used in connection with a composition, use, or method, indicates that additional elements and / or method steps may be present, but that these additions do not materially affect the manner in which the recited composition, method, or use functions. The term "consisting of," when used in connection with a composition, use, or method, excludes the presence of additional elements and / or method steps. A composition, use, or method described herein as including certain elements and / or steps may also consist essentially of those elements and / or steps in certain embodiments, and may consist of those elements and / or steps in other embodiments, whether or not those embodiments are specifically referred to.

[0037] The term "acyl," as used herein, refers to the group --C(O)R, where R is hydrogen, alkyl, aryl, heteroaryl, cycloalkyl, or heterocycloalkyl.

[0038] The term "acyloxy" refers to the group --OC(O)R, where R is alkyl.

[0039] The term "alkoxy," as used herein, refers to the group --OR, where R is alkyl, aryl, heteroaryl, cycloalkyl, or cycloheteroalkyl.

[0040] The term "alkyl," as used herein, refers to a straight-chain or branched saturated hydrocarbon group containing the specified number of carbon atoms. Examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, t-butyl, pentyl, isopentyl, t-pentyl, neopentyl, 1-methylbutyl, 2-methylbutyl, n-hexyl, and the like.

[0041] The term "alkylaminoaryl," as used herein, refers to an alkyl group, as defined herein, substituted with an aminoaryl group, as defined herein.

[0042] The term "alkylheterocycloalkyl," as used herein, refers to an alkyl group, as defined herein, substituted with one heterocycloalkyl group, as defined herein.

[0043] The term "alkylthio," as used herein, refers to the group --SR, where R is an alkyl group.

[0044] The term "amide," as used herein, refers to the group --C(O)NRR', where R and R' are independently hydrogen, alkyl, aryl, heteroaryl, cycloalkyl, or heterocycloalkyl.

[0045] The term "amino," as used herein, refers to the group --NRR', where R and R' are independently hydrogen, alkyl, aryl, heteroaryl, cycloalkyl, or heterocycloalkyl.

[0046] The term "aminoalkyl," as used herein, refers to an alkyl group, as defined herein, substituted with one or more amino groups, for example, 1, 2, or 3 amino groups.

[0047] The term "aminoaryl," as used herein, refers to an aryl group, as defined herein, substituted with an amino group.

[0048] The term "aryl," as used herein, refers to a 6- to 12-membered monocyclic or bicyclic hydrocarbon ring system in which at least one ring is aromatic. Examples of aryl include, but are not limited to, phenyl, naphthalenyl, 1,2,3,4-tetrahydro-naphthalenyl, 5,6,7,8-tetrahydro-naphthalenyl, indanyl, and the like.

[0049] The term "carboxy," as used herein, refers to the group --C(O)OR, where R is H, alkyl, aryl, heteroaryl, cycloalkyl, or cycloheteroalkyl.

[0050] The term "cyano," as used herein, refers to the group --CN.

[0051] The term "cycloalkyl," as used herein, refers to a monocyclic or bicyclic saturated hydrocarbon containing the specified number of carbon atoms. Examples of cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptane, bicyclo[2.2.1]heptane, bicyclo[3.1.1]heptane, and the like.

[0052] The term "haloalkyl," as used herein, refers to an alkyl group, as defined herein, substituted with one or more halogen atoms.

[0053] The terms "halogen" and "halo" as used herein refer to fluorine (F), bromine (Br), chlorine (Cl) and iodine (I).

[0054] The term "heteroaryl," as used herein, refers to a 6- to 12-membered monocyclic or bicyclic ring system in which at least one ring atom is a heteroatom and at least one ring is aromatic. Examples of heteroatoms include, but are not limited to, O, S, and N. Examples of heteroaryls include, but are not limited to, pyridyl, benzofuranyl, pyrazinyl, pyridazinyl, pyrimidinyl, triazinyl, quinolinyl, benzoxazolyl, benzothiazolyl, isoquinolinyl, quinazolinyl, quinoxalinyl, pyrrolyl, indolyl, and the like.

[0055] The term "heterocycloalkyl," as used herein, refers to a monocyclic or bicyclic non-aromatic ring system containing the specified number of atoms, wherein at least one ring atom is a heteroatom, such as O, S, or N. The heterocyclyl substituent can be attached via any available ring atom, such as a ring carbon or ring nitrogen. Examples of heterocycloalkyl include, but are not limited to, aziridinyl, azetidinyl, piperidinyl, morpholinyl, piperazinyl, pyrrolidinyl, and the like.

[0056] The terms "hydroxy" and "hydroxyl," as used herein, refer to the group --OH.

[0057] The term "hydroxyalkyl," as used herein, refers to an alkyl group, as defined herein, substituted with one or more hydroxy groups.

[0058] The term "nitro," as used herein, refers to the group --NO.sub.2.

[0059] The term "sulfonyl," as used herein, refers to the group --S(O)2R, where R is H, alkyl, or aryl.

[0060] The term "sulfonamide," as used herein, refers to the group --NH--S(O)2R, where R is H, alkyl, or aryl.

[0061] The terms "thio" and "thiol" as used herein refer to the group --SH.

[0062] Unless specifically stated as "unsubstituted," any alkyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl group referred to herein is understood to be "optionally substituted," i.e., each such reference includes both unsubstituted and substituted forms of those groups. For example, a reference to "-C1-C6 alkyl" includes both unsubstituted -C1-C6 alkyl and -C1-C6 alkyl substituted with one or more substituents. Examples of substituents include, but are not limited to, halogen, acyl, acyloxy, alkoxy, carboxy, hydroxy, amino, amido, nitro, cyano, azido, alkylthio, thio, sulfonyl, sulfonamido, alkyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl. In certain embodiments, each alkyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl group referred to herein is optionally substituted with one or more substituents selected from halogen, acyl, acyloxy, alkoxy, carboxy, hydroxy, amino, amido, nitro, cyano, azido, alkylthio, thio, sulfonyl, and sulfonamido.

[0063] The "substituted" chemical groups described herein may contain one substituent or multiple substituents up to the maximum valence of substitution for that group. For example, a methyl group can contain one, two, or three substituents, and a phenyl group can contain one, two, three, four, or five substituents. When a group is substituted with more than one substituent, the substituents may be the same or different.

[0064] The terms "subject" and "patient," as used herein, refer to an animal in need of treatment. The animal in need of treatment may be a human or a non-human animal, e.g., a mammal, a bird, or a fish. In certain embodiments, the subject or patient is a mammal. In some embodiments, the subject or patient is a human.

[0065] An "effective amount" of a compound or conjugate described herein with respect to a particular result to be achieved is an amount sufficient to achieve the desired result. For example, an "effective amount" of a compound when referring to killing cancer cells refers to the amount of compound sufficient to produce the killing effect.

[0066] It should be understood that the positive recitation of a feature in one embodiment constitutes a basis for excluding that feature in alternative embodiments. In particular, where a list of alternatives is presented for a given embodiment or claim, it should be understood that one or more alternatives may be deleted from the list, and that the shortened list may form alternative embodiments, whether or not such alternative embodiments are specifically mentioned.

[0067] It is contemplated that any embodiment discussed in this specification can be implemented with respect to any method, use, or composition disclosed herein, and vice versa.

[0068] Camptothecin analogues In one embodiment, the camptothecin analog compounds of the present disclosure have the formula (I): [ka] is a compound having the formula: R 1 is selected from —H, —CH3, —CHF2, —CF3, —F, —Br, —Cl, —OH, —OCH3, —OCF3, and —NH2; R 2 is selected from —H, —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3, and —OCF3; R1 is -NH2, R is R 3 or R 4 and R 1 is other than -NH2, R is R 4 and R 3 is -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , [ka] -CO2R 8 , -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; R 4 teeth, [ka] is selected from R 5 is selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, -aryl, and -(C1-C6 alkyl)-aryl; R 6 and R 7 are each independently -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , —C3-C8 heterocycloalkyl and —C(O)R 17 is selected from R 8 is selected from —H, —C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; Each R 9 are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; Each R 10 are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; Each R 10’ are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 11 is selected from —H and —C1-C6 alkyl; R 12 is -H, -C1-C6 alkyl, -CO2R 8 , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, -S(O)2R 16 and [ka] is selected from R 13 is selected from —H and —C1-C6 alkyl; R 14 and R 14’ are each independently selected from —H, C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; R 16 is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 17 is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -C3-C8 heterocycloalkyl, -(C1-C6 alkyl)-C3-C8 heterocycloalkyl, -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; R 18 and R 19 together with the N atom to which they are attached, include halogen, -C1-C6 alkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5 forming a 4-, 5-, 6- or 7-membered ring having 0 to 3 substituents selected from R 24 , R 25 and R 26 are each -C1 to C6 alkyl, X a and Xb are each independently selected from NH, O, and S; X c is selected from O, S and S(O)2; However, the compound is (S)-9-amino-11-butyl-4-ethyl-4-hydroxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione: [ka] It's surprising.

[0069] In some embodiments, the camptothecin analog is a compound of formula (I), except that R 1 is NH2, R 2 is other than H.

[0070] In some embodiments, in the compound of Formula (I), R 1 is selected from —CH 3 , —CF 3 , —OCH 3 , —OCF 3 and NH 2 .

[0071] In some embodiments, in the compound of Formula (I), R 1 is NH2.

[0072] In some embodiments, in the compound of Formula (I), R 1 is selected from —H, —CH 3 , —CF 3 , —F, —Br, —Cl, —OH, —OCH 3 , and —OCF 3 .

[0073] In some embodiments, in the compound of Formula (I), R 1 is selected from —CH 3 , —CF 3 , —OCH 3 , and —OCF 3 .

[0074] In some embodiments, in the compound of Formula (I), R 2 is selected from —H, —CH 3 , —CF 3 , —F, —Cl, —OCH 3 and —OCF 3 .

[0075] In some embodiments, in the compound of Formula (I), R 2 is selected from —CH 3 , —CF 3 , —F, —Cl, —OCH 3 and —OCF 3 .

[0076] In some embodiments, in the compound of Formula (I), R 2 is selected from -H, -F, -Br and -Cl.

[0077] In some embodiments, in the compound of Formula (I), R 2 is selected from -F, -Br and -Cl.

[0078] In some embodiments, in the compound of Formula (I), R 3 is -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , [ka] -CO2R 8 , unsubstituted -aryl, -aminoaryl, -heteroaryl and -(C1-C6 alkyl)-aminoaryl.

[0079] In some embodiments, in the compound of Formula (I), R 4 teeth, [ka] is selected from.

[0080] In some embodiments, in the compound of Formula (I), R 5 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0081] In some embodiments, in the compound of Formula (I), R 6 and R 7 are each independently -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , —C3-C8 heterocycloalkyl and —C(O)R 17 is selected from.

[0082] In some embodiments, in the compound of Formula (I), R 8 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0083] In some embodiments, in the compound of Formula (I), each R 9 is independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, and -(C1-C6 alkyl)-aryl.

[0084] In some embodiments, in the compound of Formula (I), each R 9 is independently selected from -C1-C6 alkyl and -(C1-C6 alkyl)-aryl.

[0085] In some embodiments, in the compound of Formula (I), each R 9 are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0086] In some embodiments, in the compound of Formula (I), each R 10 are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -NR 14 R14’ , -aryl and -(C1-C6 alkyl)-aryl.

[0087] In some embodiments, in the compound of Formula (I), each R 10 are independently -C1-C6 alkyl, -NR 14 R 14’ , -aryl and -(C1-C6 alkyl)-aryl.

[0088] In some embodiments, in the compound of Formula (I), each R 10 are independently unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , unsubstituted -aryl, -aminoaryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0089] In some embodiments, in the compound of Formula (I), each R 10’ are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aryl.

[0090] In some embodiments, in the compound of Formula (I), R 11 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0091] In some embodiments, in the compound of Formula (I), each R 12 is -H, -C1-C6 alkyl, -CO2R 8 , -aryl, -(C1-C6 alkyl)-aryl and -S(O)R 16 is selected from.

[0092] In some embodiments, in the compound of Formula (I), R 12 is -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -CO2R 8 , unsubstituted -aryl, -aminoaryl, -heteroaryl, -(C1-C6 alkyl)-aminoaryl, -S(O)2R 16 and [ka] is selected from.

[0093] In some embodiments, in the compound of Formula (I), R 13 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0094] In some embodiments, in the compound of Formula (I), R 14 and R 14’ are each independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0095] In some embodiments, in the compound of Formula (I), R 16 is selected from -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0096] In some embodiments, in the compound of Formula (I), R 16 is selected from unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0097] In some embodiments, in the compound of Formula (I), R 17 is selected from unsubstituted -C1-C6 alkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, -C3-C8 heterocycloalkyl, -(C1-C6 alkyl)-C3-C8 heterocycloalkyl, unsubstituted aryl, -hydroxyaryl, -aminoaryl, -heteroaryl and -(C1-C6 alkyl)-aminoaryl.

[0098] In some embodiments, in the compound of Formula (I), R 18 and R 19 together with the N atom to which they are attached, represent halogen, unsubstituted C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5 and forming a 4-, 5-, 6-, or 7-membered ring having 0 to 3 substituents selected from:

[0099] In some embodiments, in the compound of formula (I), X a and X b are each independently selected from NH and O.

[0100] Combinations of any of the foregoing embodiments for compounds of formula (I) are also envisioned, with each combination forming a separate embodiment for purposes of this disclosure.

[0101] In certain embodiments, the compound of formula (I) has formula (Ia): [ka] wherein R 1 , R 2 , R 4 , R 5 , R 8 , R 9 , R 10 , R 10’ , R 11 , R 12 , R 13 , R 14 , R14’ , R 16 , R 18 , R 19 , X a , X b and X c is as defined for formula (I).

[0102] In some embodiments, in the compound of Formula (Ia), R 1 is selected from —CH 3 , —CF 3 , —OCH 3 , —OCF 3 and —NH 2 .

[0103] In some embodiments, in the compound of Formula (Ia), R 2 is selected from —H, —CH 3 , —CF 3 , —F, —Cl, —OCH 3 and —OCF 3 .

[0104] In some embodiments, in the compound of Formula (Ia), R 2 is selected from -H, -F and -Cl.

[0105] In some embodiments, in the compound of Formula (Ia), R 4 teeth, [ka] is selected from.

[0106] In some embodiments, in the compound of Formula (Ia), R 5 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0107] In some embodiments, in the compound of Formula (Ia), R 8is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0108] In some embodiments, in the compound of Formula (Ia), each R 9 is independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, and -(C1-C6 alkyl)-aryl.

[0109] In some embodiments, in the compound of Formula (Ia), each R 9 is independently selected from -C1-C6 alkyl and -(C1-C6 alkyl)-aryl.

[0110] In some embodiments, in the compound of Formula (Ia), each R 9 are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0111] In some embodiments, in the compound of Formula (Ia), each R 10 are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ -, aryl and -(C1-C6 alkyl)-aryl.

[0112] In some embodiments, in the compound of Formula (Ia), each R 10 are independently -C1-C6 alkyl, -NR 14 R 14’ , -aryl and -(C1-C6 alkyl)-aryl.

[0113] In some embodiments, in the compound of Formula (Ia), each R 10are independently unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , unsubstituted -aryl, -aminoaryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0114] In some embodiments, in the compound of Formula (Ia), each R 10’ are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aryl.

[0115] In some embodiments, in the compound of Formula (Ia), R 11 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0116] In some embodiments, in the compound of Formula (Ia), R 12 is -H, -C1-C6 alkyl, -CO2R 8 , -aryl and -(C1-C6 alkyl)-aryl and -S(O)R 16 is selected from.

[0117] In some embodiments, in the compound of Formula (Ia), R 12 is -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -CO2R 8 , unsubstituted -aryl, -aminoaryl, -heteroaryl, -(C1-C6 alkyl)-aminoaryl, -S(O)2R 16 and [ka] is selected from.

[0118] In some embodiments, in the compound of Formula (Ia), R 13 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0119] In some embodiments, in the compound of Formula (Ia), R 14 and R 14’ are each independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0120] In some embodiments, in the compound of Formula (Ia), R 16 is selected from -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0121] In some embodiments, in the compound of Formula (Ia), R 16 is selected from unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0122] In some embodiments, in the compound of Formula (Ia), R 17 is selected from unsubstituted -C1-C6 alkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, -C3-C8 heterocycloalkyl, -(C1-C6 alkyl)-C3-C8 heterocycloalkyl, unsubstituted aryl, -hydroxyaryl, -aminoaryl, -heteroaryl and -(C1-C6 alkyl)-aminoaryl.

[0123] In some embodiments, in the compound of Formula (Ia), R 18and R 19 together with the N atom to which they are attached, represent halogen, unsubstituted C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5 and forming a 4-, 5-, 6-, or 7-membered ring having 0 to 3 substituents selected from:

[0124] In some embodiments, in the compound of Formula (Ia), X a and X b are each independently selected from NH and O.

[0125] Combinations of any of the foregoing embodiments for compounds of formula (Ia) are also envisioned, with each combination forming a separate embodiment for purposes of this disclosure.

[0126] In certain embodiments, the compound of formula (I) has formula (II): [ka] wherein R 2 is selected from —H, —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3, and —OCF3; R 20 is -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , [ka] -CO2R 8 , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, [ka] is selected from R 5 is selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 6 and R 7 are each independently -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , —C3-C8 heterocycloalkyl and —C(O)R 17 is selected from R 8 is selected from —H, —C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; Each R 9 are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; Each R 10 are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; Each R 10’ are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 11 is selected from —H and —C1-C6 alkyl; R 12 is -H, -C1-C6 alkyl, -CO2R 8 , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, -S(O)2R 16 and [ka] is selected from R 13 is selected from —H and —C1-C6 alkyl; R 14 and R 14’ are each independently selected from —H, C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; R 16is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 17 is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -C3-C8 heterocycloalkyl, -(C1-C6 alkyl)-C3-C8 heterocycloalkyl, -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; R 18 and R 19 together with the N atom to which they are attached, include halogen, -C1-C6 alkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5 forming a 4-, 5-, 6-, or 7-membered ring having 0 to 3 substituents selected from R 24 , R 25 and R 26 are each -C1 to C6 alkyl, X a and X b are each independently selected from NH, O, and S; X c is selected from O, S and S(O)2; However, the compound is other than (S)-9-amino-11-butyl-4-ethyl-4-hydroxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione.

[0127] In some embodiments, in the compound of Formula (II), R 2 is selected from —CH 3 , —CF 3 , —F, —Br, —Cl, —OH, —OCH 3 and —OCF 3 .

[0128] In some embodiments, in the compound of Formula (II), R 2 is selected from —CH 3 , —CF 3 , —F, —Cl, —OCH 3 and —OCF 3 .

[0129] In some embodiments, in the compound of Formula (II), R 2is selected from F and Cl.

[0130] In some embodiments, in the compound of Formula (II), R 20 is -H, -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5 , [ka] -(C1-C6 alkyl)-aryl, [ka] is selected from.

[0131] In some embodiments, in the compound of Formula (II), R 20 is -H, -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5 , [ka] -(C1-C6 alkyl)-aryl, [ka] is selected from.

[0132] In some embodiments, in the compound of Formula (II), R 20 is -H, -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5 , [ka] is selected from.

[0133] In some embodiments, in the compound of Formula (II), R 20 is -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , [ka] -CO2R 8 , unsubstituted aryl, -aminoaryl, -heteroaryl, -(C1-C6 alkyl)-aminoaryl, [ka] is selected from.

[0134] In some embodiments, in the compound of Formula (II), R 2 is selected from —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3 and —OCF3, and R 20 is -H, -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5 , [ka] -(C1-C6 alkyl)-aryl, [ka] is selected from.

[0135] In some embodiments, in the compound of Formula (II), R 2 is selected from —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3 and —OCF3, and R 20 is -H, -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5 , [ka] -(C1-C6 alkyl)-aryl, [ka] is selected from.

[0136] In some embodiments, in the compound of Formula (II), R 2 is selected from —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3 and —OCF3, and R 20is -H, -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5 , [ka] is selected from.

[0137] In some embodiments, in the compound of Formula (II), R 5 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0138] In some embodiments, in the compound of Formula (II), R 6 and R 7 are each independently -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, and -C(O)R 17 is selected from.

[0139] In some embodiments, in the compound of Formula (II), R 6 is H and R 7 is -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , —C3-C8 heterocycloalkyl and —C(O)R 17 is selected from.

[0140] In some embodiments, in the compound of Formula (II), R 6 is H and R 7 is -H, -C1-C6 alkyl, -C3-C8 cycloalkyl and -C(O)R 17 is selected from.

[0141] In some embodiments, in the compound of Formula (II), R 6 and R 7are each independently -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , —C3-C8 heterocycloalkyl and —C(O)R 17 is selected from.

[0142] In some embodiments, in the compound of Formula (II), R 8 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0143] In some embodiments, in the compound of Formula (II), each R 9 is independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, and -(C1-C6 alkyl)-aryl.

[0144] In some embodiments, in the compound of Formula (II), each R 9 is independently selected from -C1-C6 alkyl and -(C1-C6 alkyl)-aryl.

[0145] In some embodiments, in the compound of Formula (II), each R 9 are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0146] In some embodiments, in the compound of Formula (II), each R 10 are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , -aryl and -(C1-C6 alkyl)-aryl.

[0147] In some embodiments, in the compound of Formula (II), each R 10 are independently -C1-C6 alkyl, -NR 14 R 14’ , -aryl and -(C1-C6 alkyl)-aryl.

[0148] In some embodiments, in the compound of Formula (II), each R 10 are independently unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , unsubstituted -aryl, -aminoaryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0149] In some embodiments, in the compound of Formula (II), each R 10’ are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aryl.

[0150] In some embodiments, in the compound of Formula (II), R 11 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0151] In some embodiments, in the compound of Formula (II), R 12 is -H, -C1-C6 alkyl, -CO2R 8 , -aryl, -(C1-C6 alkyl)-aryl and -S(O)R 16 is selected from.

[0152] In some embodiments, in the compound of Formula (II), R 12is -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -CO2R 8 , unsubstituted -aryl, -aminoaryl, -heteroaryl, -(C1-C6 alkyl)-aminoaryl, -S(O)2R 16 and [ka] is selected from.

[0153] In some embodiments, in the compound of Formula (II), R 13 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0154] In some embodiments, in the compound of Formula (II), R 14 and R 14’ are each independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0155] In some embodiments, in the compound of Formula (II), R 16 is selected from -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0156] In some embodiments, in the compound of Formula (II), R 16 is selected from unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0157] In some embodiments, in the compound of Formula (II), R 17is —C1 to C6 alkyl.

[0158] In some embodiments, in the compound of Formula (II), R 17 is selected from unsubstituted -C1-C6 alkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, -C3-C8 heterocycloalkyl, -(C1-C6 alkyl)-C3-C8 heterocycloalkyl, unsubstituted aryl, -hydroxyaryl, -aminoaryl, -heteroaryl and -(C1-C6 alkyl)-aminoaryl.

[0159] In some embodiments, in the compound of Formula (II), R 18 and R 19 together with the N atom to which they are attached, represent halogen, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5 and forming a 4-, 5-, 6-, or 7-membered ring having 0 to 3 substituents selected from:

[0160] In some embodiments, in the compound of formula (II), X a and X b are each independently selected from NH and O.

[0161] Combinations of any of the foregoing embodiments for compounds of formula (II) are also contemplated, with each combination forming a separate embodiment for purposes of this disclosure.

[0162] In certain embodiments, the compound of formula (I) has the formula (IIa): [ka] wherein R 20 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 10’ , R11 , R 12 , R 13 , R 14 , R 14’ , R 16 , R 17 , R 18 , R 19 , X a , X b and X c is as defined for formula (II).

[0163] In some embodiments, in the compound of Formula (IIa), R 20 is -H, -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5 , [ka] -(C1-C6 alkyl)-aryl, [ka] is selected from.

[0164] In some embodiments, in the compound of Formula (IIa), R 20 is -H, -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5 , [ka] -(C1-C6 alkyl)-aryl, [ka] is selected from.

[0165] In some embodiments, in the compound of Formula (IIa), R 20 is -H, -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5 , [ka] is selected from.

[0166] In some embodiments, in the compound of Formula (IIa), R 20 is -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , [ka] -CO2R 8 , unsubstituted aryl, -aminoaryl, -heteroaryl, -(C1-C6 alkyl)-aminoaryl, [ka] is selected from.

[0167] In some embodiments, in the compound of Formula (IIa), R 5 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0168] In some embodiments, in the compound of Formula (IIa), R 6 and R 7 are each independently -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, and -C(O)R 17 is selected from.

[0169] In some embodiments, in the compound of Formula (IIa), R 6 is H and R 7 is -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , —C3-C8 heterocycloalkyl and —C(O)R 17 is selected from.

[0170] In some embodiments, in the compound of Formula (IIa), R 6 is H and R 7 is -H, -C1-C6 alkyl, -C3-C8 cycloalkyl and -C(O)R 17 is selected from.

[0171] In some embodiments, in the compound of Formula (IIa), R 6 and R 7 are each independently -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , —C3-C8 heterocycloalkyl and —C(O)R 17 is selected from.

[0172] In some embodiments, in the compound of Formula (IIa), R 8 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0173] In some embodiments, in the compound of Formula (IIa), each R 9 is independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, and -(C1-C6 alkyl)-aryl.

[0174] In some embodiments, in the compound of Formula (IIa), each R 9 is independently selected from -C1-C6 alkyl and -(C1-C6 alkyl)-aryl.

[0175] In some embodiments, in the compound of Formula (IIa), each R 9are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0176] In some embodiments, in the compound of Formula (IIa), each R 10 are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ -, aryl and -(C1-C6 alkyl)-aryl.

[0177] In some embodiments, in the compound of Formula (IIa), each R 10 are independently -C1-C6 alkyl, -NR 14 R 14’ , -aryl and -(C1-C6 alkyl)-aryl.

[0178] In some embodiments, in the compound of Formula (IIa), each R 10 are independently unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , unsubstituted -aryl, -aminoaryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0179] In some embodiments, in the compound of Formula (IIa), each R 10’ are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aryl.

[0180] In some embodiments, in the compound of Formula (IIa), R11 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0181] In some embodiments, in the compound of Formula (IIa), R 12 is -H, -C1-C6 alkyl, -CO2R 8 , -aryl, -(C1-C6 alkyl)-aryl and -S(O)R 16 is selected from.

[0182] In some embodiments, in the compound of Formula (IIa), R 12 is -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -CO2R 8 , unsubstituted -aryl, -aminoaryl, -heteroaryl, -(C1-C6 alkyl)-aminoaryl, -S(O)2R 16 and [ka] is selected from.

[0183] In some embodiments, in the compound of Formula (IIa), R 13 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0184] In some embodiments, in the compound of Formula (IIa), R 14 and R 14’ are each independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0185] In some embodiments, in the compound of Formula (IIa), R 16is selected from -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0186] In some embodiments, in the compound of Formula (IIa), R 16 is selected from unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0187] In some embodiments, in the compound of Formula (IIa), R 17 is —C1 to C6 alkyl.

[0188] In some embodiments, in the compound of Formula (IIa), R 17 is selected from unsubstituted C1-C6 alkyl, —C1-C6 hydroxyalkyl, —C3-C8 cycloalkyl, —C3-C8 heterocycloalkyl, —(C1-C6 alkyl)-C3-C8 heterocycloalkyl, unsubstituted -aryl, -hydroxyaryl, -aminoaryl, -heteroaryl and -(C1-C6 alkyl)-aminoaryl.

[0189] In some embodiments, in the compound of Formula (IIa), R 18 and R 19 together with the N atom to which they are attached, represent halogen, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5 and forming a 4-, 5-, 6-, or 7-membered ring having 0 to 3 substituents selected from:

[0190] In some embodiments, in the compound of Formula (IIa), X a and X b are each independently selected from NH and O.

[0191] Combinations of any of the foregoing embodiments for compounds of formula (IIa) are also envisioned, with each combination forming a separate embodiment for purposes of this disclosure.

[0192] In certain embodiments, the compound of formula (I) has formula (III): [ka] wherein R 2 is selected from —H, —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3, and —OCF3; R 15 is selected from —H, —CH3, —CHF2, —CF3, —F, —Br, —Cl, —OH, —OCH3, and —OCF3; R 4 teeth, [ka] is selected from R 5 is selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 8 is selected from —H, —C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; Each R 9 are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; Each R 10 are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; Each R 10’ are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R11 is selected from —H and —C1-C6 alkyl; R 12 is -H, -C1-C6 alkyl, -CO2R 8 , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, -S(O)2R 16 and [ka] is selected from R 13 is selected from —H and —C1-C6 alkyl; R 14 and R 14’ are each independently selected from —H, C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; R 16 is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 18 and R 19 together with the N atom to which they are attached, include halogen, -C1-C6 alkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5 forming a 4-, 5-, 6-, or 7-membered ring having 0 to 3 substituents selected from R 24 , R 25 and R 26 are each -C1 to C6 alkyl, X a and X b are each independently selected from NH, O, and S; X c is selected from O, S and S(O)2.

[0193] In some embodiments, in the compound of Formula (III), R 2 is selected from —H, —CH 3 , —CF 3 , —F, —Cl, —OCH 3 and —OCF 3 .

[0194] In some embodiments, in the compound of Formula (III), R 2 is selected from -H, -F and -Cl.

[0195] In some embodiments, in the compound of Formula (III), R 15 is selected from —CH 3 , —CF 3 , —OCH 3 , and —OCF 3 .

[0196] In some embodiments, in the compound of Formula (III), R 15 is selected from —CH3 and —OCH3.

[0197] In some embodiments, in the compound of Formula (III), R 2 is selected from -H, -F and -Cl, R 15 is selected from —CH3, —CF3, —OCH3 and —OCF3.

[0198] In some embodiments, in the compound of Formula (III), R 2 is selected from -H, -F and -Cl, R 15 is selected from —CH3 and —OCH3.

[0199] In some embodiments, in the compound of Formula (III), R 4 teeth, [ka] is selected from.

[0200] In some embodiments, in the compound of Formula (III), R 5 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0201] In some embodiments, in the compound of Formula (III), R8 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0202] In some embodiments, in the compound of Formula (III), each R 9 is independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, and -(C1-C6 alkyl)-aryl.

[0203] In some embodiments, in the compound of Formula (III), each R 9 is independently selected from -C1-C6 alkyl and -(C1-C6 alkyl)-aryl.

[0204] In some embodiments, in the compound of Formula (III), each R 9 are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0205] In some embodiments, in the compound of Formula (III), each R 10 are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , -aryl and -(C1-C6 alkyl)-aryl.

[0206] In some embodiments, in the compound of Formula (III), each R 10 are independently -C1-C6 alkyl, -NR 14 R 14’ , -aryl and -(C1-C6 alkyl)-aryl.

[0207] In some embodiments, in the compound of Formula (III), each R 10 are independently unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , unsubstituted -aryl, -aminoaryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0208] In some embodiments, in the compound of Formula (III), each R 10’ are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aryl.

[0209] In some embodiments, in the compound of Formula (III), R 11 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0210] In some embodiments, in the compound of Formula (III), R 12 is -H, -C1-C6 alkyl, -CO2R 8 , -aryl, -(C1-C6 alkyl)-aryl and -S(O)R 16 is selected from.

[0211] In some embodiments, in the compound of Formula (III), R 12 is -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -CO2R 8 , unsubstituted -aryl, -aminoaryl, -heteroaryl, -(C1-C6 alkyl)-aminoaryl, -S(O)2R 16 and [ka] is selected from.

[0212] In some embodiments, in the compound of Formula (III), R 13 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0213] In some embodiments, in the compound of Formula (III), R 14 and R 14’ are each independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0214] In some embodiments, in the compound of Formula (III), R 16 is selected from -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0215] In some embodiments, in the compound of Formula (III), R 16 is selected from unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0216] In some embodiments, in the compound of Formula (III), R 18 and R 19 together with the N atom to which they are attached, represent halogen, unsubstituted C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5 and forming a 4-, 5-, 6-, or 7-membered ring having 0 to 3 substituents selected from:

[0217] In some embodiments, in the compound of formula (III), X a and X b are each independently selected from NH and O.

[0218] Combinations of any of the foregoing embodiments for compounds of formula (III) are also envisioned, with each combination forming a separate embodiment for purposes of this disclosure.

[0219] In certain embodiments, the compound of formula (I) has formula (IIIa) or (IIIb): [ka] wherein R 4 , R 5 , R 8 , R 9 , R 10 , R 10’ , R 11 , R 12 , R 13 , R 14 , R 14’ , R 16 , R 18 , R 19 , X a , X b and X c is as defined for formula (III).

[0220] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), R 4 teeth, [ka] is selected from.

[0221] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), R 5is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0222] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), R 8 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0223] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), each R 9 is independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, and -(C1-C6 alkyl)-aryl.

[0224] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), each R 9 is independently selected from -C1-C6 alkyl and -(C1-C6 alkyl)-aryl.

[0225] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), each R 9 are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0226] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), each R 10 are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -NR 14 R 14’-, aryl and -(C1-C6 alkyl)-aryl.

[0227] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), each R 10 are independently -C1-C6 alkyl, -NR 14 R 14’ , -aryl and -(C1-C6 alkyl)-aryl.

[0228] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), each R 10 are independently unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , unsubstituted -aryl, -aminoaryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0229] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), each R 10’ are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aryl.

[0230] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), R 11 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0231] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), R 12 is -H, -C1-C6 alkyl, -CO2R 8, -aryl, -(C1-C6 alkyl)-aryl and -S(O)R 16 is selected from.

[0232] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), R 12 is -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -CO2R 8 , unsubstituted -aryl, -aminoaryl, -heteroaryl, -(C1-C6 alkyl)-aminoaryl, -S(O)2R 16 and [ka] is selected from.

[0233] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), R 13 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0234] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), R 14 and R 14’ are each independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0235] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), R 16 is selected from -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0236] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), R 16is selected from unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0237] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), R 18 and R 19 together with the N atom to which they are attached, represent halogen, unsubstituted C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5 and forming a 4-, 5-, 6-, or 7-membered ring having 0 to 3 substituents selected from:

[0238] In some embodiments, in the compound of Formula (IIIa) or Formula (IIIb), X a and X b are each independently selected from NH and O.

[0239] Combinations of any of the foregoing embodiments for each of the compounds of formula (IIIa) and formula (IIIb) are also envisioned, with each combination forming a separate embodiment for purposes of this disclosure.

[0240] As noted above, certain compounds of Formula (I), (Ia), (II), (IIa), (III), (IIIa), or (IIIb) may contain one or more free amino, hydroxy, carbonyl (e.g., keto or aldehyde), or carboxylic acid groups. Protected forms of compounds of Formula (I), (Ia), (II), (IIa), (III), (IIIa), or (IIIb), in which the free amino, hydroxy, carbonyl (e.g., keto or aldehyde), or carboxylic acid groups are otherwise protected with a suitable protecting group, are also encompassed by the present disclosure. The term "protecting group" refers to a chemical group that, when attached to a potentially reactive functional group, masks, reduces, or prevents the reactivity of the functional group. Typically, protecting groups can be selectively removed as desired during the course of a synthesis.

[0241] Protecting groups are well known in the art, and various examples are described, for example, in "Protective Groups in Organic Chemistry" (Greene, W. & Wuts, PGM, 2006, John Wiley & Sons). Examples of amino-protecting groups include, but are not limited to, formyl, acetyl, trifluoroacetyl, benzyl (Bn), benzoyl (Bz), benzyloxycarbonyl (CBZ), tert-butoxycarbonyl (Boc), trimethylsilyl (TMS), 2-trimethylsilyl-ethanesulfonyl (TES), trityl, substituted trityl, tosyl, phthalimide, allyloxycarbonyl (Alloc), and 9-fluorenylmethyloxycarbonyl (FMOC). Examples of hydroxy protecting groups include, but are not limited to, acetyl, benzyl (Bn), t-butyl, benzoyl (Bz), β-methoxyethoxymethyl ether (MEM), dimethoxytrityl (DMT), methoxymethyl ether (MOM), methoxytrityl [(4-methoxyphenyl)diphenylmethyl] (MMT), p-methoxybenzyl ether (PMB), p-methoxyphenyl ether (PMP), methylthiomethyl ether, pivaloyl (Piv), tetrahydropyranyl (THP), tetrahydrofuran (THF), trityl, trimethylsilyl (TMS), tert-butyldimethylsilyl (TBDMS or TBS), tri-isopropylsilyloxymethyl (TOM), and triisopropylsilyl (TIPS). Examples of carbonyl protecting groups include, but are not limited to, acetals, hemi-acetals, and ketals. Examples of carboxylic acid protecting groups include, but are not limited to, methyl esters, benzyl esters, tert-butyl esters, silyl esters, orthoesters, and oxazolines.

[0242] Certain embodiments of the present disclosure relate to protected compounds of Formula (II) or (IIa) in which the C10 free amino group is protected. Some embodiments relate to protected compounds of Formula (II) or (IIa) in which the C10 free amino group is protected with a formyl, acetyl, trifluoroacetyl, benzyl (Bn), benzoyl (Bz), benzyloxycarbonyl (CBZ), tert-butoxycarbonyl (Boc), trityl, substituted trityl, tosyl, phthalimido, allyloxycarbonyl (Alloc), or 9-fluorenylmethyloxycarbonyl (FMOC) group. Some embodiments relate to protected forms of compounds of Formula (II) or (IIa) in which the C10 free amino group is protected with an acetyl group.

[0243] In certain embodiments, each of the alkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl groups as defined in any one of formulas (I), (Ia), (II), (IIa), (III), (IIIa), or (IIIb) is optionally substituted with one or more substituents selected from halogen, acyl, acyloxy, alkoxy, carboxy, hydroxy, amino, amido, nitro, cyano, azido, alkylthio, thio, sulfonyl, sulfonamido, alkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl. In some embodiments, each of the alkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl groups as defined in any one of formulas (I), (Ia), (II), (IIa), (III), (IIIa), or (IIIb) is optionally substituted with one or more substituents selected from halogen, acyl, acyloxy, alkoxy, carboxy, hydroxy, amino, amido, nitro, cyano, azido, alkylthio, thio, sulfonyl, and sulfonamido.

[0244] In certain embodiments of the present disclosure, the camptothecin analog is a compound having formula (I) or a protected form thereof, and is selected from the compounds shown in Table 1. [Table 1-1] [Table 1-2] [Table 1-3] [Table 1-4] [Table 1-5] [Table 1-6] [Table 1-7] [Table 1-8] [Table 1-9] [Table 1-10] [Table 1-11] [Table 1-12] [Table 1-13]

[0245] In certain embodiments, the camptothecin analog is a compound having formula (II) or a protected form thereof and is selected from the compounds shown in Table 2. [Table 2-1] [Table 2-2] [Table 2-3] [Table 2-4] [Table 2-5] [Table 2-6] [Table 2-7]

[0246] In certain embodiments, the camptothecin analog is a compound having formula (III) or a protected form thereof and is selected from the compounds shown in Table 3. [Table 3-1] [Table 3-2] [Table 3-3] [Table 3-4] [Table 3-5] [Table 3-6] [Table 3-7]

[0247] References to compounds of formula (I) throughout the remainder of this disclosure should be understood to include, in various embodiments, compounds of formula (Ia), formula (II), formula (IIa), formula (III), formula (IIIa), and formula (IIIb) to the same extent as if the embodiments listing each of these formulas individually were specifically listed.

[0248] In certain embodiments, the compounds of formula (I) may have sufficiently acidic groups, sufficiently basic groups, or both functional groups, and therefore may react with many organic and inorganic bases, or organic and inorganic acids, to form pharmaceutically acceptable salts. The term "pharmaceutically acceptable salts" as used herein refers to salts of the compounds of formula (I) that are substantially non-toxic to living organisms. Typical pharmaceutically acceptable salts include salts prepared by reacting the compounds of formula (I) with pharmaceutically acceptable inorganic or organic acids or organic or inorganic bases. Such salts are known as acid addition salts and base addition salts.

[0249] Acids commonly utilized to form acid addition salts are inorganic acids, including, but not limited to, hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, and phosphoric acid, as well as organic acids, including, but not limited to, p-toluenesulfonic acid, methanesulfonic acid, oxalic acid, p-bromophenylsulfonic acid, carbonic acid, succinic acid, citric acid, benzoic acid, and acetic acid. Examples of pharmaceutically acceptable salts include sulfate, pyrosulfate, bisulfite, sulfite, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, bromide, iodide, acetate, propionate, decanoate, caprylate, acrylate, formate, hydrochloride, dihydrochloride, isobutyrate, caproate, heptanoate, propiolate, oxalate, malonate, succinate, suberate, sebacate, fumarate, maleate, butyne-1,4-dioate, hexahydrate, and benzoate. Pharmaceutically acceptable acid addition salts of particular interest include, but are not limited to, syn-1,6-dioate, benzoate, chlorobenzoate, methylbenzoate, hydroxybenzoate, methoxybenzoate, phthalate, xylenesulfonate, phenylacetate, phenylpropanoate, phenylbutyrate, citrate, lactate, gamma-hydroxybutyrate, glycolate, tartrate, methanesulfonate, propanesulfonate, naphthalene-1-sulfonate, naphthalene-2-sulfonate, and mandelate. Pharmaceutically acceptable acid addition salts of particular interest are salts formed with inorganic acids such as hydrochloric acid and hydrobromic acid, and salts formed with organic acids such as maleic acid and methanesulfonic acid.

[0250] Salts of amine groups may also include quaternary ammonium salts in which the amino nitrogen carries a suitable organic group such as an alkyl, lower alkenyl, lower alkynyl, or aralkyl moiety.

[0251] Base addition salts include salts derived from inorganic bases such as ammonium or alkali or alkaline earth metal hydroxides, carbonates, bicarbonates, etc. Bases useful in preparing pharmaceutically acceptable salts include, but are not limited to, sodium hydroxide, potassium hydroxide, ammonium hydroxide, potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, calcium hydroxide, and calcium carbonate.

[0252] Those skilled in the art will appreciate that the particular counterion forming part of a pharmaceutically acceptable salt is usually not of critical nature, so long as the salt as a whole is pharmacologically acceptable and the counterion does not impart undesirable properties to the overall salt.

[0253] Certain embodiments relate to pharmaceutically acceptable solvates of compounds of formula (I). Those skilled in the art will understand that certain compounds of formula (I) can be combined with solvents such as water, methanol, ethanol, or acetonitrile to form pharmaceutically acceptable solvates such as the corresponding hydrates, methanolates, ethanolates, or acetonitriles. Other examples of solvents that can be used to prepare solvates include isopropanol, dimethyl sulfoxide, ethyl acetate, acetic acid, ethanolamine, and acetone, as well as miscible combinations of solvate mixtures that will be recognized by those skilled in the art.

[0254] Preparation of camptothecin analogues Camptothecin analogs of Formula (I) can be prepared from commercially available starting materials and reagents by standard synthetic organic chemistry methods. See also Li, et al., 2019, ACS Med. Chem. Lett., 10(10):1386-1392 and U.S. Patent Application Publication No. US2004 / 0266803. Representative examples of suitable synthetic routes are described in detail in the Examples provided herein (see also FIG. 1). Those skilled in the art will recognize that alternative methods may be utilized to synthesize camptothecin analogs of Formula (I), and therefore, the approaches described herein are not intended to be exhaustive.

[0255] Complex Certain embodiments of the present disclosure relate to conjugates of compounds of formula (I) comprising one or more compounds of formula (I) conjugated to a targeting moiety via one or more linkers.

[0256] The conjugate of the present disclosure may comprise one or more compounds of formula (I) conjugated to a targeting moiety. For example, multiple compounds of formula (I) may be conjugated to a targeting moiety by binding the compounds to multiple different sites on the targeting moiety. Alternatively, or in addition, multiple compounds of formula (I) may be conjugated to a targeting moiety by using one or more polyvalent linkers, each of which allows multiple compounds to be bound to one site on the targeting moiety.

[0257] Thus, certain embodiments of the present disclosure include compounds of formula (X): T-[L-(D) m ] n (X) A complex of the formula: T is a targeting moiety, L is a linker, D is a camptothecin analog described herein; m is an integer between 1 and 4, n is an integer between 1 and 10 for the complex.

[0258] In certain embodiments, in the conjugate of formula (X), m is between 1 and 2. In some embodiments, m is 1.

[0259] In some embodiments, in the conjugate of formula (X), n is between 1 and 8, e.g., between 2 and 8, or between 2 and 6. In some embodiments, n is between 2 and 4.

[0260] As discussed above and reflected by the parameters m and n in formula (X), targeting moiety "T" can be conjugated to two or more compounds "D" of formula (I). One of skill in the art will understand that while any particular targeting moiety T is conjugated to an integer number of compounds D, analysis of a preparation of conjugates to determine the ratio of compound D to targeting moiety T may yield a non-integer result reflecting a statistical average. This ratio of compound D to targeting moiety T is sometimes commonly referred to as the drug-to-antibody ratio, or "DAR." Thus, conjugate preparations having a non-integer DAR are intended to be encompassed by formula (X). One of skill in the art will understand that the term "DAR" may also be utilized to define conjugates comprising targeting moieties other than antibodies.

[0261] Camptothecin Analogue D According to the present disclosure, the conjugate of formula (X) comprises a camptothecin analog as drug moiety D, the camptothecin analog being a compound of formula (I).

[0262] In certain embodiments, in the conjugate of Formula (X), D is a compound of Formula (Ia), Formula (II), Formula (IIa), Formula (III), Formula (IIIa), or Formula (IIIb). In certain embodiments, in the conjugate of Formula (X), D is a compound selected from the compounds shown in Tables 1-3.

[0263] Certain embodiments of the present disclosure relate to conjugates having formula (X), wherein D is a compound of formula (IV): [ka] is a compound of the formula R 1a is selected from —H, —CH3, —CHF2, —CF3, —F, —Br, —Cl, —OH, —OCH3, —OCF3, and —NH2; R 2a is selected from —H, —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3, and —OCF3; X is -O-, -S- or -NH-, and R 4a teeth, [ka] wherein * is the point of attachment to X and p is 1, 2, 3 or 4; or X is O and R 4a -X- is [ka] is selected from R 5a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 8a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl; Each R 9a are independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; or R 9a does not exist, X b =X, Each R 10a are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, and [ka] is selected from Each R 10a’are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; Each R 10b are independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 11a is absent or is -C1-C6 alkyl, R 12a is -C1 to C6 alkyl, -CO2R 8a , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, -S(O)2R 16a and [ka] is selected from R 13a is selected from —H and —C1-C6 alkyl; R 14a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl; R 14a’ is selected from H, —C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; R 16a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 21 is -C1-C6 alkyl, -C3-C8 cycloalkyl and -(C1-C6 alkyl)-OR 5a is selected from R 22 and R 23 are each independently selected from -H, -halogen, C1-C6 alkyl, and -C3-C8 cycloalkyl; R 24 , R 25 and R 26 are each -C1 to C6 alkyl, Xa and X b are each independently selected from NH, O, and S; X c is selected from O, S and S(O)2; [ka] indicates the point of attachment to the linker L.

[0264] In some embodiments, in the compound of formula (IV), R 1a is selected from —CH 3 , —CF 3 , —OCH 3 , —OCF 3 and —NH 2 .

[0265] In some embodiments, in the compound of formula (IV), R 1a is selected from —CH 3 , —CF 3 , —OCH 3 , and —OCF 3 .

[0266] In some embodiments, in the compound of formula (IV), R 1a is selected from —CH 3 , —OCH 3 and NH 2 .

[0267] In some embodiments, in the compound of formula (IV), R 1a is selected from —CH3 and —OCH3.

[0268] In some embodiments, in the compound of formula (IV), R 2a is selected from —H, —CH 3 , —CF 3 , —F, —Cl, —OCH 3 and —OCF 3 .

[0269] In some embodiments, in the compound of formula (IV), R 2a is selected from -H, -F and -Cl.

[0270] In some embodiments, in the compound of formula (IV), R 2a is -F.

[0271] In some embodiments, in the compound of Formula (IV), X is —O—, —S—, or —NH—, and R 4a teeth, [ka] is selected from.

[0272] In some embodiments, in the compound of Formula (IV), X is —O— or —NH—.

[0273] In some embodiments, in the compound of Formula (IV), each R 9a is independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, and -(C1-C6 alkyl)-aryl.

[0274] In some embodiments, in the compound of Formula (IV), each R 9a is independently selected from -C1-C6 alkyl and -(C1-C6 alkyl)-aryl.

[0275] In some embodiments, in the compound of Formula (IV), each R 10a are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -(C1-C6 alkyl)-aryl, and [ka] is selected from.

[0276] In some embodiments, in the compound of Formula (IV), each R 10a are independently -C1-C6 alkyl, -aryl, -(C1-C6 alkyl)-aryl, and [ka] is selected from.

[0277] In some embodiments, in the compound of formula (IV), R 12ais -C1-C6 alkyl, -aryl, -(C1-C6 alkyl)-aryl and -S(O)2R 16 is selected from.

[0278] In some embodiments, in the compound of formula (IV), R 13a is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0279] In some embodiments, in the compound of formula (IV), R 14a’ is selected from H, unsubstituted —C1-C6 alkyl, —C1-C6 haloalkyl, —C1-C6 hydroxyalkyl, —C1-C6 aminoalkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl.

[0280] In some embodiments, in the compound of formula (IV), R 16a is selected from -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0281] In some embodiments, in the compound of formula (IV), R 22 and R 23 are each independently selected from -H, -halogen, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 aminoalkyl, -C1-C6 hydroxyalkyl, and -C3-C8 cycloalkyl.

[0282] In some embodiments, in the compound of formula (IV), X a and X b are each independently selected from NH and O.

[0283] Combinations of any of the foregoing embodiments for compounds of formula (IV) are also envisioned, with each combination forming a separate embodiment for purposes of this disclosure.

[0284] Certain embodiments of the present disclosure relate to conjugates having formula (X), wherein D is a compound of formula (V): [ka] is a compound of the formula R 2a is selected from —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3 and —OCF3; R 20a is -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , [ka] -CO2R 8 , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, [ka] is selected from R 5 is selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 6 and R 7 are each independently -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , —C3-C8 heterocycloalkyl and —C(O)R 17 is selected from R 8 is selected from —H, —C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; Each R 9 are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; Each R 10are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, and [ka] is selected from Each R 10’ are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 11 is selected from —H and —C1-C6 alkyl; R 12 is -H, -C1-C6 alkyl, -CO2R 8 , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, -S(O)2R 16 and [ka] is selected from R 13 is selected from —H and —C1-C6 alkyl; R 14 and R 14’ are each independently selected from —H, C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; R 16 is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 17 is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -C3-C8 heterocycloalkyl, -(C1-C6 alkyl)-C3-C8 heterocycloalkyl, -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; R 18 and R 19 together with the N atom to which they are attached, include halogen, -C1-C6 alkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5forming a 4-, 5-, 6-, or 7-membered ring having 0 to 3 substituents selected from R 24 , R 25 and R 26 are each -C1 to C6 alkyl, X a and X b are each independently selected from NH, O, and S; X c is selected from O, S and S(O)2; [ka] indicates the point of attachment to the linker L.

[0285] In some embodiments, in the compound of Formula (V), R 2a is selected from —CH 3 , —CF 3 , —F, —Cl, —OCH 3 and —OCF 3 .

[0286] In some embodiments, in the compound of Formula (V), R 2a is selected from —CF3, —F, —Cl and —OCH3.

[0287] In some embodiments, in the compound of Formula (V), R 2a is F.

[0288] In some embodiments, in the compound of Formula (V), R 20a is -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , [ka] -CO2R 8 , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, [ka] is selected from.

[0289] In some embodiments, in the compound of Formula (V), R 20a is -H, -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5 , [ka] -(C1-C6 alkyl)-aryl, [ka] is selected from.

[0290] In some embodiments, in the compound of Formula (V), R 20a is -H, -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5 , [ka] -(C1-C6 alkyl)-aryl, [ka] is selected from.

[0291] In some embodiments, in the compound of Formula (V), R 20a is -H, -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5 , [ka] is selected from.

[0292] In some embodiments, in the compound of Formula (V), R 20a is -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , [ka] -CO2R 8, unsubstituted aryl, aminoaryl, heteroaryl, (C1-C6 alkyl) aminoaryl, [ka] is selected from.

[0293] In some embodiments, in the compound of Formula (V), R 6 and R 7 are each independently -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, and -C(O)R 17 is selected from.

[0294] In some embodiments, in the compound of Formula (V), R 6 is H and R 7 is -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , —C3-C8 heterocycloalkyl and —C(O)R 17 is selected from.

[0295] In some embodiments, in the compound of Formula (V), R 6 is H and R 7 is -H, -C1-C6 alkyl, -C3-C8 cycloalkyl and -C(O)R 17 is selected from.

[0296] In some embodiments, in the compound of Formula (V), R 6 and R 7 are each independently -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5 , —C3-C8 heterocycloalkyl and —C(O)R 17 is selected from.

[0297] In some embodiments, in the compound of Formula (V), R 8is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0298] In some embodiments, in the compound of Formula (V), each R 9 is independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, and -(C1-C6 alkyl)-aryl.

[0299] In some embodiments, in the compound of Formula (V), each R 9 is independently selected from -C1-C6 alkyl and -(C1-C6 alkyl)-aryl.

[0300] In some embodiments, in the compound of Formula (V), each R 9 are independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0301] In some embodiments, in the compound of Formula (V), each R 10 are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -NR 14 R 14’ , -aryl and -(C1-C6 alkyl)-aryl.

[0302] In some embodiments, in the compound of Formula (V), each R 10 are independently -C1-C6 alkyl, -NR 14 R 14’ , -aryl and -(C1-C6 alkyl)-aryl.

[0303] In some embodiments, in the compound of Formula (V), R 11is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0304] In some embodiments, in the compound of Formula (V), R 12 is -H, -C1-C6 alkyl, -aryl, -(C1-C6 alkyl)-aryl and -S(O)2R 16 is selected from.

[0305] In some embodiments, in the compound of Formula (V), R 12 is -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -CO2R 8 , unsubstituted -aryl, -aminoaryl, -heteroaryl, -(C1-C6 alkyl)-aminoaryl, -S(O)2R 16 and [ka] is selected from.

[0306] In some embodiments, in the compound of Formula (V), R 13 is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0307] In some embodiments, in the compound of Formula (V), R 14 and R 14’ are each independently selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0308] In some embodiments, in the compound of Formula (V), R 16 is selected from -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0309] In some embodiments, in the compound of Formula (V), R 16 is selected from unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, -C3-C8 cycloalkyl, unsubstituted -aryl, -aminoaryl, -heteroaryl, and -(C1-C6 alkyl)-aminoaryl.

[0310] In some embodiments, in the compound of Formula (V), R 17 is selected from unsubstituted -C1-C6 alkyl, -C3-C8 cycloalkyl, -C3-C8 heterocycloalkyl, -(C1-C6 alkyl)-C3-C8 heterocycloalkyl, unsubstituted -aryl, -hydroxyaryl, -aminoaryl, -heteroaryl and -(C1-C6 alkyl)-aminoaryl.

[0311] In some embodiments, in the compound of Formula (V), R 18 and R 19 together with the N atom to which they are attached, represent halogen, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 aminoalkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, and -(C1-C6 alkyl)-OR 5 and forming a 4-, 5-, 6-, or 7-membered ring having 0 to 3 substituents selected from:

[0312] In some embodiments, in the compound of Formula (V), R 17 is —C1 to C6 alkyl.

[0313] In some embodiments, in the compound of formula (V), X a and X b are each independently selected from NH and O.

[0314] Combinations of any of the foregoing embodiments for compounds of formula (V) are also envisioned, with each combination forming a separate embodiment for purposes of this disclosure.

[0315] Certain embodiments of the present disclosure relate to conjugates having formula (X), wherein D is a compound of formula (VI): [ka] is a compound of the formula R 2a is selected from —H, —CH3, —CF3, —F, —Br, —Cl, —OH, —OCH3, and —OCF3; X is -O-, -S- or -NH-, and R 25 is -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5a , -CO2R 8a , —C(O)—, -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, [ka] wherein * is the point of attachment to X and p is 1, 2, 3 or 4; or X is O and R 25 -X- is [ka] is selected from R 5a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 6a is selected from —H, —C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; R 7a is -C1-C6 alkyl, -C3-C8 cycloalkyl, -(C1-C6 alkyl)-OR 5a , —C3-C8 heterocycloalkyl and —C(O)R 17a is selected from R 8a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl; Each R 9a are independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; or R 9a does not exist, X b =X, Each R 10a are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, and [ka] is selected from Each R 10a’ are independently selected from -H, -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; Each R 10b are independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 11a is absent or is -C1-C6 alkyl, R 12a is -C1 to C6 alkyl, -CO2R 8a , -aryl, -heteroaryl, -(C1-C6 alkyl)-aryl, -S(O)2R 16a and [ka] is selected from R 13a is selected from —H and —C1-C6 alkyl; R 14a is selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl; R 14a’ is selected from H, —C1-C6 alkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl; R 16ais selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -heteroaryl, and -(C1-C6 alkyl)-aryl; R 17a is selected from -C1-C6 alkyl, -C3-C8, -C3-C8 heterocycloalkyl, -(C1-C6 alkyl)-C3-C8 heterocycloalkyl, -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl; R 21 is -C1-C6 alkyl, -C3-C8 cycloalkyl and -(C1-C6 alkyl)-OR 5a is selected from R 22 and R 23 are each independently selected from -H, -halogen, C1-C6 alkyl, and -C3-C8 cycloalkyl; R 24 , R 25 and R 26 are each -C1 to C6 alkyl, X a and X b are each independently selected from NH, O, and S; X c is selected from O, S and S(O)2; [ka] indicates the point of attachment to the linker L.

[0316] In some embodiments, in the compound of formula (VI), R 2a is selected from —CH 3 , —CF 3 , —F, —Br, —Cl, —OH, —OCH 3 and —OCF 3 .

[0317] In some embodiments, in the compound of formula (VI), R 2a is selected from —CH 3 , —CF 3 , —F, —Cl, —OCH 3 and —OCF 3 .

[0318] In some embodiments, in the compound of formula (VI), R 2a is selected from F and Cl.

[0319] In some embodiments, in the compound of formula (VI), R 2a is F.

[0320] In some embodiments, in the compound of Formula (VI), X is —O—, —S—, or —NH—, and R 25 is -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5a , -(C1-C6 alkyl)-aryl, [ka] Alternatively, X is O and R 25 -X- is [ka] is selected from.

[0321] In some embodiments, in the compound of Formula (VI), X is —O—, —S—, or —NH—, and R 25 is -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5a , -(C1-C6 alkyl)-aryl, [ka] is selected from.

[0322] In some embodiments, in the compound of Formula (VI), X is —O—, —S—, or —NH—, and R 25 is -C1-C6 alkyl, -(C1-C6 alkyl)-OR 5a , [ka] is selected from.

[0323] In some embodiments, in the compound of Formula (VI), X is —O—, —S—, or —NH—, and R 25 teeth, [ka] is selected from.

[0324] In some embodiments, in the compound of Formula (VI), X is —O— or —NH—.

[0325] In some embodiments, in the compound of formula (VI), R 6a is H.

[0326] In some embodiments, in the compound of formula (VI), R 6a is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C3-C8 cycloalkyl, and -C3-C8 heterocycloalkyl.

[0327] In some embodiments, in the compound of formula (VI), R 7a is -C1-C6 alkyl, -C3-C8 cycloalkyl and -C(O)R 17a is selected from.

[0328] In some embodiments, in the compound of Formula (VI), each R 9a is independently selected from -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, and -(C1-C6 alkyl)-aryl.

[0329] In some embodiments, in the compound of Formula (VI), each R 9a is independently selected from -C1-C6 alkyl and -(C1-C6 alkyl)-aryl.

[0330] In some embodiments, in the compound of Formula (VI), each R 10a are independently -C1-C6 alkyl, -C3-C8 cycloalkyl, -aryl, -(C1-C6 alkyl)-aryl, and [ka] is selected from.

[0331] In some embodiments, in the compound of Formula (VI), each R 10a are independently -C1-C6 alkyl, -aryl, -(C1-C6 alkyl)-aryl, and [ka] is selected from.

[0332] In some embodiments, in the compound of formula (VI), R 12a is -C1-C6 alkyl, -aryl, -(C1-C6 alkyl)-aryl and -S(O)2R 16a is selected from.

[0333] In some embodiments, in the compound of formula (VI), R 13a is selected from -H, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, and -C1-C6 aminoalkyl.

[0334] In some embodiments, in the compound of formula (VI), R 14a’ is selected from H, unsubstituted —C1-C6 alkyl, —C1-C6 haloalkyl, —C1-C6 hydroxyalkyl, —C1-C6 aminoalkyl, —C3-C8 cycloalkyl, and —C3-C8 heterocycloalkyl.

[0335] In some embodiments, in the compound of formula (VI), R 16a is selected from -aryl, -heteroaryl and -(C1-C6 alkyl)-aryl.

[0336] In some embodiments, in the compound of formula (VI), R 17a is —C1 to C6 alkyl.

[0337] In some embodiments, in the compound of formula (VI), R 22 and R 23are each independently selected from -H, -halogen, unsubstituted -C1-C6 alkyl, -C1-C6 haloalkyl, -C1-C6 hydroxyalkyl, -C1-C6 aminoalkyl, and -C3-C8 cycloalkyl.

[0338] In some embodiments, in the compound of formula (VI), X a and X b are each independently selected from NH and O.

[0339] Combinations of any of the foregoing embodiments for compounds of formula (VI) are also envisioned, with each combination forming a separate embodiment for purposes of this disclosure.

[0340] In certain embodiments, each of the alkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl groups as defined in any one of formulas (IV), (V), or (VI) is optionally substituted with one or more substituents selected from halogen, acyl, acyloxy, alkoxy, carboxy, hydroxy, amino, amido, nitro, cyano, azido, alkylthio, thio, sulfonyl, sulfonamido, alkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl. In some embodiments, each of the alkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl groups as defined in any one of formulas (IV), (V), or (VI) is optionally substituted with one or more substituents selected from halogen, acyl, acyloxy, alkoxy, carboxy, hydroxy, amino, amido, nitro, cyano, azido, alkylthio, thio, sulfonyl, and sulfonamido.

[0341] Targeting moiety T The targeting moiety T included in the conjugate of formula (X) is a molecule that binds to, reactively associates with, or complexes with a receptor, antigen, or other receptor moiety associated with a given target cell population. Generally, the targeting moiety T functions to deliver the camptothecin analog D to the specific target cell population with which the targeting moiety T reacts. Examples of targeting moieties include, but are not limited to, proteins (e.g., antibodies, antibody fragments, and growth factors), glycoproteins, peptides (e.g., bombesin and gastrin-releasing peptide), lectins, vitamins (e.g., folic acid), and nutrient transport molecules (e.g., transferrin).

[0342] Generally, the targeting moiety T is attached to the linker L through a heteroatom of the targeting moiety T, such as sulfur (e.g., of a sulfhydryl group), oxygen (e.g., of a carbonyl, carboxyl, or hydroxyl group), or nitrogen (e.g., of a primary or secondary amino group). These heteroatoms may be naturally present in the targeting moiety T, or may be incorporated by engineering and / or expression, or may be incorporated by chemical or enzymatic modification using techniques known in the art.

[0343] In some embodiments, the targeting moiety, T, is an antibody. Accordingly, certain embodiments of the present disclosure relate to antibody drug conjugates (ADCs) having the general formula (X), where the targeting moiety, T, is an antibody.

[0344] When the conjugate is an ADC, the antibody included as the targeting moiety T can be a full-size polyclonal or monoclonal antibody, an antigen-binding antibody fragment (e.g., Fab, scFab, Fab', F(ab')2, Fv, or scFv), a domain antibody (dAb), or an antibody mimetic (e.g., an affibody, DARPin, anticalin, versabody, duocalin, lipocalin, or avimer). Antibodies are generally directed against a specific antigen, e.g., a disease-associated antigen such as a tumor-associated antigen, an antigen associated with an autoimmune disease, or a viral antigen.

[0345] In certain embodiments in which the conjugate is an ADC, the targeting moiety, T, is a monoclonal antibody, an antigen-binding antibody fragment (e.g., Fab, scFab, Fab', F(ab')2, Fv, or scFv), or a domain antibody (dAb).

[0346] Methods for producing polyclonal and monoclonal antibodies are known in the art. By way of example, monoclonal antibodies may be produced by methods including, but not limited to, the hybridoma technique originally described by Kohler and Milstein (1975, Nature 256:495-497), the human B-cell hybridoma technique (Kozbor et al., 1983, Immunology Today 4:72), the EBV-hybridoma technique (Cole et al., 1985, Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, Inc., pp. 77-96), and the selective lymphocyte antibody method (SLAM) (Babcook, et al., 1996, Proc Natl Acad Sci USA, 93(15):7843-8; McLean et al., 2005, J Immunol., 174(8):4768-4778). Antibodies of the various immunoglobulin classes, including IgG, IgM, IgE, IgA, and IgD, and their subclasses, may be used as targeting moieties in various embodiments, hi some embodiments, the targeting moiety is an IgG class antibody.

[0347] In certain embodiments, the targeting moiety T may be a monoclonal antibody. The monoclonal antibody may be, for example, a non-human monoclonal antibody (e.g., a murine antibody), a human monoclonal antibody, a humanized monoclonal antibody, or a chimeric antibody (e.g., a human-murine antibody). Human monoclonal antibodies may be produced by any of a number of techniques known in the art (e.g., Teng et al., 1983, Proc. Natl. Acad. Sci. USA 80:7308-7312; Kozbor et al., 1983, Immunology Today 4:72-79; Olsson et al., 1983, Meth. Enzymol. 92:3-16; Huse et al., 1989, Science 246:1275-1281 and U.S. Patent No. 8,012,714). Chimeric and humanized monoclonal antibodies are described, for example, in International Patent Publication Nos. WO 87 / 02671 and WO 86 / 01533; European Patent Publication Nos. 0 184 187; 0 171 496 and 0 173 494; U.S. Pat. Nos. 4,816,567 and 5,225,539; Berter et al., 1988, Science 240:1041-1043; Liu et al., 1987, J. Immunol., 139:3521-3526; Sun et al., 1987, Proc. Natl. Acad. Sci. USA, 84:214-218; Wood et al., 1985, Nature, 314:446-449; Shaw et al. Antibodies immunospecific for a given target antigen can also be obtained commercially.

[0348] In certain embodiments, the antibody included in the conjugate may be a bispecific or multispecific antibody. Methods for making bispecific and multispecific antibodies are known in the art (e.g., Milstein et al., 1983, Nature, 305:537-539; Traunecker et al., 1991, EMBO J., 10:3655-3659; Suresh et al., 1986, Meth. Enzymol., 121:210; Rodrigues et al., 1993, J. Immunol., 151:6954-6961; Carter et al., 1992, Bio / Technology, 10:163-167; Carter et al., 1995, J. Hematotherapy, 4:463-470; Merchant et al., 1998, Nature Biotechnology, 16:677-681, and International (PCT) Publication Nos. WO94 / 04690, WO2012 / 032080, WO2012 / 058768, and WO2013 / 063702).

[0349] In certain embodiments, the targeting moiety T included in the conjugate is an antibody or antigen-binding antibody fragment that binds to a tumor-associated antigen (TAA). Examples of tumor-associated antigens include 5T4, ADAM-9, ALK, AMHRII, ASCT2, Axl, B7-H3, BCMA, C4.4a, CA6, CA9, CanAg, CD123, CD138, CD142, CD166, CD184, CD19, CD20, CD205, CD22, CD248, CD25, CD3, CD30, CD33, CD352, CD37, CD38, CD40L, CD44v6, CD45, CD46, CD48, CD51, CD56, CD7, CD8, CD9, CD10, CD11, CD12 ... D70, CD71, CD74, CD79b, CDH6, CEACAM5, CEACAM6, cKIT, CLDN18.2, CLDN6, CLL-1, c-MET, Cripto, CSP-1, CXCR5, DLK-1, DLL3, DP EP3, Dysadherin, EFNA4, EGFR, EGFRviii, ENPP3, EpCAM, EphA2, EphA3, ETBR, FGFR2, FGFR3, FLT3, FRα, FSH, GCC, GD2, GD3, Globo H, GPC-1, GPC3, gpNMB, HER-2, HER-3, HLA-DR, HSP90, IGF-1R, IL-13R, IL1RAP, IL7R, IL4R, KAAG-1, LAMP-1, Lewis Y antigen, LGALS3BP, LGR5, LH / hCG, LHRH, LIV-1, LRP-1, LRRC15, Ly6E, MAGE, MSLN, MET, MICA, MICB, MT1-MMP, MTX3, MTX5, MUC1, MUC16, NaPi2b, nectin-4, NOTCH3, OAcGD2, OX001L, p-cadherin, PD-1, PD-L1, phosphatidylserine (PS), polymorphic epithelial mucin These include, but are not limited to, PEM, prolactin receptor (PRLR), PSMA, PTK7, RNF43, ROR1, ROR2, SAIL, SLAMF7, SLC44A4, SLITRK6, SSTR2, STEAP-1, STING, sialyl-Tn, TIM-1, TM4SF1, TNFα, TRA, TROP-2, TAG-72, TA-MUC1, TIM-3, UPK2, and UPK1b.

[0350] Linker L The conjugate of formula (X) comprises a linker, L, which is a bifunctional or polyfunctional moiety capable of linking one or more camptothecin analogs, D, to a targeting moiety, T. A bifunctional (or monovalent) linker, L, links a single compound, D, to a single site on the targeting moiety, T, whereas a polyfunctional (or polyvalent) linker, L, links two or more compounds, D, to a single site on the targeting moiety, T. A linker that links one compound, D, to two or more sites on the targeting moiety, T, may also be considered polyfunctional in certain embodiments.

[0351] The linker L comprises a functional group capable of reacting with a targeting group(s) on the targeting moiety T and at least one functional group capable of reacting with a targeting group on the camptothecin analog D. Suitable functional groups are known in the art and include, for example, those described in Bioconjugate Techniques (G.T. Hermanson, 2013, Academic Press). Groups on the targeting moiety T and the camptothecin analog D that can serve as targeting groups for linker attachment include, but are not limited to, thiol, hydroxyl, carboxyl, amine, aldehyde, and ketone groups.

[0352] Non-limiting examples of functional groups that can react with thiols include maleimides, haloacetamides, haloacetyls, activated esters (e.g., succinimide esters, 4-nitrophenyl esters, pentafluorophenyl esters, and tetrafluorophenyl esters), anhydrides, acid chlorides, sulfonyl chlorides, isocyanates, and isothiocyanates. Also useful in this context are the "self-stabilizing" maleimides described in Lyon et al., 2014, Nat. Biotechnol., 32:1059-1062.

[0353] Non-limiting examples of functional groups that can react with amines include activated esters (e.g., N-hydroxysuccinamide (NHS) esters, sulfo-NHS esters, imidoesters such as Traut's reagent, tetrafluorophenyl (TFP) esters, and sulfodichlorophenyl esters), isothiocyanates, aldehydes, and acid anhydrides (e.g., diethylenetriaminepentaacetic anhydride (DTPA)). Other examples include succinimido-1,1,3,3-tetramethyluronium tetrafluoroborate (TSTU) and benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate (PyBOP).

[0354] Non-limiting examples of functional groups that can react with electrophilic groups such as aldehyde or ketone carbonyl groups include hydrazide, oxime, amino, hydrazine, thiosemicarbazone, hydrazine carboxylate, and arylhydrazide.

[0355] In certain embodiments where the targeting moiety T is an antibody, the linker L may contain a functional group that allows for bridging of cysteines between two chains on the antibody, such as a ThioBridge™ linker (Badescu et al., 2014, Bioconjug. Chem. 25:1124-1136), a dithiomaleimide (DTM) linker (Behrens et al., 2015, Mol. Pharm. 12:3986-3998), a dithioaryl (TCEP) pyridazinedione-based linker (Lee et al., 2016, Chem. Sci., 7:799-802), or a dibromopyridazinedione-based linker (Maruani et al., 2015, Nat. Commun., 6:6645).

[0356] Alternatively, the targeting moiety T may be modified to contain a non-natural reactive group, such as an azide, that allows conjugation to the linker via a complementary reactive group on the linker. For example, conjugation of the linker to the targeting moiety may utilize click chemistry reactions, such as the azide-alkyne cycloaddition (AAC) reaction, which has been successfully used in the development of antibody-drug conjugates (see, e.g., Chio & Bane, 2020, Methods Mol. Biol., 2078:83-97). The AAC reaction may be a copper-catalyzed AAC (CuAAC) reaction, which involves coupling of an azide with a linear alkyne, or a strain-promoted AAC (SPAAC) reaction, which involves coupling of an azide with a cyclooctyne.

[0357] The linker L may be a cleavable linker or a non-cleavable linker. A cleavable linker is a linker that is easily cleaved under certain conditions, such as intracellular conditions (e.g., in endosomes or lysosomes) or in the vicinity of target cells (e.g., tumor microenvironment). Examples include protease-sensitive, acid-sensitive, or reduction-sensitive linkers. In contrast, non-cleavable linkers generally rely on the degradation of the antibody in cells, which results in the release of the amino acid-linker-drug moiety.

[0358] Examples of cleavable linkers include linkers containing an amino acid sequence that is a cleavage recognition sequence for a protease. Many such cleavage recognition sequences are known in the art. For conjugates that are not intended to be internalized by cells, an amino acid sequence that is recognized and cleaved by a protease present in the extracellular matrix surrounding target cells, such as cancer cells, may be used. Examples of extracellular tumor-associated proteases include plasmin, matrix metalloproteinases (MMPs), elastase, and kallikrein-related peptidases.

[0359] For conjugates intended to be internalized by cells, the linker L may comprise an amino acid sequence that is recognized and cleaved by an endosomal or lysosomal protease, examples of which include cathepsins B, C, D, H, L, and S, and legumain.

[0360] The cleavage recognition sequence may be, for example, a dipeptide, tripeptide, or tetrapeptide. Non-limiting examples of dipeptide recognition sequences that may be included in the cleavable linker include, but are not limited to, Ala-(D)Asp, Ala-Lys, Ala-Phe, Asn-Lys, Asn-(D)Lys, Asp-Val, His-Val, Ile-Cit, Ile-Pro, Ile-Val, Leu-Cit, Me3Lys-Pro, Met-Lys, Met-(D)Lys, NorVal-(D)Asp, Phe-Arg, Phe-Cit, Phe-Lys, PhenylGly-(D)Lys, Pro-(D)Lys, Trp-Cit, Val-Ala, Val-(D)Asp, Val-Cit, Val-Gly, Val-Gln, and Val-Lys. Examples of tri- and tetrapeptide cleavage sequences include, but are not limited to, Ala-Ala-Asn, Ala-Val-Cit, (D)Ala-Phe-Lys, Asp-Val-Ala, Asp-Val-Cit, Gly-Cit-Val, Lys-Val-Ala, Lys-Val-Cit, Met-Cit-Val, (D)Phe-Phe-Lys, Asn-Pro-Val, Ala-Leu-Ala-Leu, Gly-Phe-Leu-Gly, Gly-Gly-Phe-Gly, and Gly-Phe-Gly-Gly.

[0361] Further examples of cleavable linkers include disulfide-containing linkers such as N-succinimidyl-4-(2-pyridyldithio)butanoate (SPDB) and N-succinimidyl-4-(2-pyridyldithio)-2-sulfobutanoate (sulfo-SPDB). Disulfide-containing linkers may optionally contain additional groups that provide steric hindrance adjacent to the disulfide bond, such as geminal dimethyl groups, to improve the extracellular stability of the linker. Other cleavable linkers include linkers that are hydrolyzable at a specific pH or within a pH range, such as hydrazone linkers. Linkers containing a combination of these functional groups may also be useful; for example, linkers containing both hydrazones and disulfides are known in the art.

[0362] Further examples of cleavable linkers are linkers containing β-glucuronides that can be cleaved by β-glucuronidase, an enzyme present in lysosomes and tumor stroma (see, e.g., De Graaf et al., 2002, Curr. Pharm. Des. 8:1391-1403, and International Patent Publication No. WO 2007 / 011968). The β-glucuronide can also function to increase the hydrophilicity of the linker L.

[0363] Another example of a linker that is cleaved intracellularly to increase hydrophilicity is a linker that contains a pyrophosphate diester moiety (see, e.g., Kern et al., 2016, J Am Chem Soc., 138:2430-1445).

[0364] In certain embodiments, the linker L included in the conjugate of formula (X) is a cleavable linker. In some embodiments, the linker L comprises a cleavage recognition sequence. In some embodiments, the linker L may comprise an amino acid sequence that is recognized and cleaved by a lysosomal protease.

[0365] The cleavable linker may optionally further comprise one or more additional functional groups, such as a self-immolative group, a self-leaving group, a stretcher, or a hydrophilic moiety.

[0366] Self-immolative and self-leaving groups used in linkers include, for example, p-aminobenzyl (PAB) and p-aminobenzyloxycarbonyl (PABC) groups, as well as methylated ethylenediamine (MED). Other examples of self-immolative groups include, but are not limited to, heterocyclic derivatives, such as aromatic compounds electronically similar to PAB or PABC groups, such as the 2-aminoimidazole-5-methanol derivative described in U.S. Pat. No. 7,375,078. Other examples include groups that undergo cyclization upon amide bond hydrolysis, such as substituted and unsubstituted 4-aminobutyric acid amide (Rodrigues et al., 1995, Chemistry Biology 2:223-227) and 2-aminophenylpropionic acid amide (Amsberry, et al., 1990, J. Org. Chem. 55:5867-5877). Self-immolative / self-leaving groups are generally attached to the amino or hydroxyl group of compound D. Self-immolative / self-leaving groups, alone or in combination, are often included in peptide-based linkers, but may also be included in other types of linkers.

[0367] Stretchers used in linkers for drug conjugates include, for example, alkylene groups and fatty acid, dibasic acid, amine, or diamine-based stretchers, such as diglycolate, malonate, caproate, and caproamide. Other stretchers include, for example, glycine-based stretchers and polyethylene glycol (PEG) or monomethoxypolyethylene glycol (mPEG) stretchers.

[0368] PEG and mPEG stretchers can also function as hydrophilic moieties within the linker. For example, PEG or mPEG can be included in the linker either "linearly" or as a pendant group to increase the hydrophilicity of the linker (see, e.g., U.S. Patent Application Publication No. US2016 / 0310612). Various PEG-containing linkers are commercially available from companies such as Quanta BioDesign, Ltd. (Plain City, OH). Other hydrophilic groups that may optionally be incorporated into the linker L include, for example, β-glucuronide, sulfonate, carboxylate, and pyrophosphate diester.

[0369] In certain embodiments, the conjugate of formula (X) may comprise a cleavable linker. In certain embodiments, the conjugate of formula (X) may comprise a peptide-containing linker. In some embodiments, the conjugate of formula (X) may comprise a protease-cleavable linker.

[0370] In some embodiments, in the conjugate of formula (X), the linker L is of formula (XI): [ka] is a cleavable linker having the formula: Z is a linking group that attaches the linker to the targeting group on the targeting moiety T; Str is a stretcher AA1 and AA2 are each independently an amino acid, and AA1-[AA2] r forms a protease cleavage site, X is a self-immolative group, q is 0 or 1, r is 1, 2 or 3; s is 0, 1 or 2; # is the point of attachment to the targeting moiety T, % is the point of attachment to camptothecin analogue D.

[0371] In some embodiments, q is 1 in the linker of formula (XI).

[0372] In some embodiments, in the linker of formula (XI), s is 1. In some embodiments, in the linker of formula (XI), s is 0.

[0373] In some embodiments, in the linker of formula (XI): Z is [ka] where # is the point of attachment to T and * is the point of attachment to the rest of the linker.

[0374] In some embodiments, in the linker of formula (XI), Str is [ka] is selected from During the ceremony, R is H or C1-C6 alkyl; t is an integer between 2 and 10, u is an integer between 1 and 10.

[0375] In some embodiments, in the linker of formula (XI), Str is [ka] is selected from During the ceremony, R is H or C1-C6 alkyl; t is an integer between 2 and 10, u is an integer between 1 and 10.

[0376] In some embodiments, in the linker of formula (XI), AA1-[AA2] rare Ala-(D)Asp, Ala-Lys, Ala-Phe, Asn-Lys, Asn-(D)Lys, Asp-Val, His-Val, Ile-Cit, Ile-Pro, Ile-Val, Leu-Cit, Me3Lys-Pro, Met-Lys, Met-(D)Lys, NorVa It has a sequence selected from l-(D)Asp, Phe-Arg, Phe-Cit, Phe-Lys, phenylGly-(D)Lys, Pro-(D)Lys, Trp-Cit, Val-Ala, Val-(D)Asp, Val-Cit, Val-Gly, Val-Gln and Val-Lys. Examples of tri- and tetrapeptide cleavage sequences include, but are not limited to, Ala-Ala-Asn, Ala-Val-Cit, (D)Ala-Phe-Lys, Asp-Val-Ala, Asp-Val-Cit, Gly-Cit-Val, Lys-Val-Ala, Lys-Val-Cit, Met-Cit-Val, (D)Phe-Phe-Lys, Asn-Pro-Val, Ala-Leu-Ala-Leu, Gly-Phe-Leu-Gly, Gly-Gly-Phe-Gly, and Gly-Phe-Gly-Gly.

[0377] In some embodiments, in the conjugate of formula (X), m is 1 and the linker L has formula (XI).

[0378] In certain embodiments, in the conjugate of formula (X), the linker L is of formula (XII): [ka] is a cleavable linker having the formula: Z is a linking group that attaches the linker to the targeting group on the targeting moiety T; Str is a stretcher AA1 and AA2 are each independently an amino acid, and AA1-[AA2] r forms a protease cleavage site, Y is -NH-CH2- or -NH-CH2-C(O)-; q is 0 or 1, r is 1, 2 or 3; v is 0 or 1, # is the point of attachment to the targeting moiety T, % is the point of attachment to camptothecin analogue D.

[0379] In some embodiments, q is 1 in the linker of formula (XII).

[0380] In some embodiments, in the linker of formula (XII), s is 0. In some embodiments, in the linker of formula (XII), s is 1.

[0381] In some embodiments, in the linker of formula (XII): Z is [ka] where # is the point of attachment to T and * is the point of attachment to the rest of the linker.

[0382] In some embodiments, in the linker of formula (XII), Str is [ka] is selected from During the ceremony, R is H or C1-C6 alkyl; t is an integer between 2 and 10, u is an integer between 1 and 10.

[0383] In some embodiments, in the linker of formula (XII), Str is [ka] is selected from During the ceremony, R is H or C1-C6 alkyl; t is an integer between 2 and 10, u is an integer between 1 and 10.

[0384] In some embodiments, in the linker of formula (XII), AA1-[AA2] r are Ala-(D)Asp, Ala-Lys, Ala-Phe, Asn-Lys, Asn-(D)Lys, Asp-Val, His-Val, Ile-Cit, Ile-Pro, Ile-Val, Leu-Cit, Me3Lys-Pro, Met-Lys, Met-(D)Lys, NorVa It has a sequence selected from l-(D)Asp, Phe-Arg, Phe-Cit, Phe-Lys, phenylGly-(D)Lys, Pro-(D)Lys, Trp-Cit, Val-Ala, Val-(D)Asp, Val-Cit, Val-Gly, Val-Gln and Val-Lys. Examples of tri- and tetrapeptide cleavage sequences include, but are not limited to, Ala-Ala-Asn, Ala-Val-Cit, (D)Ala-Phe-Lys, Asp-Val-Ala, Asp-Val-Cit, Gly-Cit-Val, Lys-Val-Ala, Lys-Val-Cit, Met-Cit-Val, (D)Phe-Phe-Lys, Asn-Pro-Val, Ala-Leu-Ala-Leu, Gly-Phe-Leu-Gly, Gly-Gly-Phe-Gly, and Gly-Phe-Gly-Gly.

[0385] In some embodiments, in the conjugate of formula (X), m is 1 and the linker L has formula (XII).

[0386] In some embodiments, the conjugate of formula (X) may include a disulfide-containing linker. In some embodiments, in the conjugate of formula (X), the linker L is represented by formula (XIII): [ka] is a cleavable linker having the formula: Z is a linking group that attaches the linker to the targeting group on the targeting moiety T; Q is -(CH2) p -or-(CH2CH2O) qand p and q are each independently an integer between 1 and 10; each R is independently H or C1-C6 alkyl; n is 1, 2 or 3; # is the point of attachment to the targeting moiety T, % is the point of attachment to camptothecin analogue D.

[0387] In some embodiments, in the conjugate of formula (X), m is 1 and the linker L has formula (XIII).

[0388] In some embodiments, the conjugate of formula (X) may include a β-glucuronide-containing linker.

[0389] Various non-cleavable linkers for linking drugs to targeting moieties are known in the art and may, in certain embodiments, be useful in the conjugate compositions of the present disclosure. Examples of non-cleavable linkers include linkers having an N-succinimidyl ester or N-sulfosuccinimidyl ester moiety for reaction with a cell-binding agent and a maleimide or haloacetyl-based moiety for reaction with a drug, or vice versa. An example of such a non-cleavable linker is one based on sulfosuccinimidyl-4-[N-maleimidomethyl]cyclohexane-1-carboxylate (sulfo-SMCC). Sulfo-SMCC conjugation generally occurs via a maleimide group that reacts with the sulfhydryl (thiol, -SH) of compound D, while the sulfo-NHS ester is reactive to primary amines (found on lysines and the N-termini of proteins or peptides) of targeting moiety T. Other non-limiting examples of such linkers include N-succinimidyl 4-(maleimidomethyl)cyclohexanecarboxylate (SMCC), N-succinimidyl-4-(N-maleimidomethyl)-cyclohexane-1-carboxy-(6-amidocaproate) ("long chain" SMCC or LC-SMCC), κ-maleimidoundecanoic acid N-succinimidyl ester (KMUA), γ-maleimidobutyric acid N-succinimidyl ester (GMBS), ε-maleimidocaproate, These include those based on N-hydroxysuccinimide acid ester (EMCS), m-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS), N-(α-maleimidoacetoxy)-succinimide ester (AMAS), succinimidyl-6-(β-maleimidopropionamido)hexanoate (SMPH), N-succinimidyl 4-(p-maleimidophenyl)-butyrate (SMPB), and N-(p-maleimidophenyl)isocyanate (PMPI).Other examples include those containing haloacetyl-based functional groups such as N-succinimidyl-4-(iodoacetyl)-aminobenzoate (SIAB), N-succinimidyl iodoacetate (SIA), N-succinimidyl bromoacetate (SBA), and N-succinimidyl 3-(bromoacetamido)propionate (SBAP).

[0390] Non-limiting examples of drug-linkers comprising camptothecin analogs of Formula (I) are shown in Table 4 (FIG. 4), Table 5 (FIG. 5), and Table 6 (FIG. 6). Non-limiting examples of conjugates comprising these drug-linkers are shown in Table 7 (FIG. 7), Table 8 (FIG. 8), and Table 9 (FIG. 9). In certain embodiments, a conjugate of Formula (X) comprises a drug-linker selected from those shown in Tables 4, 5, and 6. In certain embodiments, a conjugate of Formula (X) is selected from those shown in Tables 7, 8, and 9, where T is a targeting moiety and n is an integer between 1 and 10. In some embodiments, a conjugate of Formula (X) is selected from those shown in Tables 7, 8, and 9, where T is a targeting moiety and n is an integer between 2 and 8. In some embodiments, a conjugate of Formula (X) is selected from those shown in Tables 7, 8, and 9, where T is an antibody or an antigen-binding antibody fragment.

[0391] preparation Conjugates of formula (X) can be prepared by standard methods known in the art (see, for example, Bioconjugate Techniques (GT Hermanson, 2013, Academic Press)). Various linkers and linker components are commercially available or can be prepared using standard synthetic organic chemistry techniques (see, for example, March's Advanced Organic Chemistry (Smith & March, 2006, Sixth Ed., Wiley); Toki et al., (2002) J. Org. Chem. 67:1866-1872; Frisch et al., (1997) Bioconj. Chem. 7:180-186; Bioconjugate Techniques (GT Hermanson, 2013, Academic Press)). Additionally, various antibody-drug conjugation services are commercially available from companies such as Lonza Inc. (Allendale, NJ), Abzena PLC (Cambridge, UK), ADC Biotechnology (St. Asaph, UK), Baxter BioPharma Solutions (Baxter Healthcare Corporation, Deerfield, IL), and Piramel Pharma Solutions (Grangemouth, UK).

[0392] In general, preparation of the conjugate involves first preparing a drug-linker DL comprising one or more camptothecin analogs of Formula (I) and a linker L, and then conjugating the drug-linker DL to an appropriate group on the targeting moiety T. However, ligation of the linker L to the targeting moiety T followed by ligation of the targeting moiety-linker TL to one or more camptothecin analogs D of Formula (I) is an alternative approach available in some embodiments.

[0393] Suitable groups on compound D of formula (I) for attachment of linker L in any of the above approaches include, but are not limited to, thiol groups, amine groups, carboxylic acid groups, and hydroxyl groups. In some embodiments of the present disclosure, linker L is attached to the compound through a hydroxyl or amine group on compound D of formula (I).

[0394] Suitable groups on the targeting moiety T for attachment of the linker L in any of the above approaches include sulfhydryl groups (e.g., in the side chain of a cysteine ​​residue), amino groups (e.g., in the side chain of a lysine residue), carboxylic acid groups (e.g., in the side chain of an aspartic acid or glutamic acid residue), and carbohydrate groups.

[0395] For example, the targeting moiety T may contain one or more naturally occurring sulfhydryl groups that allow the targeting moiety T to be attached to the linker L via the sulfhydryl group's sulfur atom. Alternatively, the targeting moiety T may contain one or more lysine residues that can be chemically modified to introduce one or more sulfhydryl groups. Reagents that can be used to modify lysine residues include, but are not limited to, N-succinimidyl S-acetylthioacetate (SATA), N-succinimidyl-3-(2-pyridyldithio)propionate ("SPDP"), and 2-iminothiolane hydrochloride (Traut's reagent). Alternatively, the targeting moiety T may contain one or more carbohydrate groups that can be chemically modified to contain one or more sulfhydryl groups.

[0396] Carbohydrate groups on the targeting moiety T can also be oxidized to provide aldehyde (-CHO) groups (see, e.g., Laguzza et al., 1989, J. Med. Chem. 32(3):548-55), which could then react with the linker L, e.g., via a hydrazine or hydroxylamine group on the linker L.

[0397] The targeting moiety, T, can also be modified to include additional cysteine ​​residues (see, e.g., U.S. Pat. Nos. 7,521,541; 8,455,622; and 9,000,130) or unnatural amino acids that provide reactive handles, such as selenomethionine, p-acetylphenylalanine, formylglycine, or p-azidomethyl-L-phenylalanine (see, e.g., Hofer et al., 2009, Biochemistry, 48:12047-12057; Axup et al., 2012, PNAS, 109:16101-16106; Wu et al., 2009, PNAS, 106:3000-3005; Zimmerman et al., 2014, Bioconj. Chem., 25:351-361), to allow site-specific conjugation. Alternatively, the targeting moiety T may be modified to include a non-naturally occurring reactive group such as an azide that allows for conjugation to a linker via a complementary reactive group on the linker, e.g., by click chemistry (see, e.g., Chio & Bane, 2020, Methods Mol. Biol., 2078:83-97).

[0398] Other protocols for modifying proteins for the attachment or association of a linker L are known in the art, including those described in Coligan et al., Current Protocols in Protein Science, Vol. 2, John Wiley & Sons (2002).

[0399] In embodiments in which the targeting moiety, T, is an antibody, several different reactive groups on antibodies may serve as conjugation sites, including the ε-amino group on a lysine residue, a pendant carbohydrate moiety, the side chain carboxylic acid group on an aspartic acid or glutamic acid residue, a cysteine-cysteine ​​disulfide group, and a cysteine ​​thiol group. The amino acids used for conjugation may be part of the native sequence of the antibody or may be incorporated by site-directed engineering techniques known in the art, as described above.

[0400] Alternatively, antibody-drug conjugates can be prepared using the enzyme transglutaminase, e.g., bacterial transglutaminase (BTG) from Streptomyces mobaraensis (see, e.g., Jeger et al., 2010, Angew. Chem. Int. Ed., 49:9995-9997). BTG forms an amide bond between the side chain carboxamide of glutamine (typically an amine acceptor on an antibody) and an alkyleneamino group (typically an amine donor on a drug-linker), which can be, for example, the ε-amino group of lysine or a 5-amino-n-pentyl group. Antibodies can also be modified to include a glutamine-containing peptide, or "tag," that enables BTG conjugation to be used to conjugate the antibody with a drug-linker (see, e.g., U.S. Patent Application Publication No. US2013 / 0230543 and International (PCT) Publication No. WO2016 / 144608).

[0401] A similar conjugation approach utilizes the enzyme sortase A. In this approach, an antibody is typically engineered to contain a sortase A recognition motif (LPXTG, where X is any naturally occurring amino acid), and the drug-linker is designed to contain an oligoglycine motif (typically GGG) to enable sortase A-mediated transpeptidation (see, e.g., Beerli, et al., 2015, PLos One, 10:e0131177; Chen et al., 2016, Nature: Scientific Reports, 6:31899).

[0402] Once conjugation is complete, the average number of compounds of Formula (I) conjugated to the targeting moiety T (i.e., the "drug-to-antibody ratio" or DAR) may be determined by standard techniques, such as UV / VIS spectroscopy, ELISA-based techniques, chromatographic techniques such as hydrophobic interaction chromatography (HIC), UV-MALDI mass spectrometry (MS), and MALDI-TOF MS. In addition, the distribution of drug-linked forms (e.g., the proportion of targeting moiety T containing 0, 1, 2, 3, etc. compounds of Formula (I) D) may also optionally be analyzed. Various techniques for assessing DAR distribution are known in the art, including MS (with or without an accompanying chromatographic separation step), hydrophobic interaction chromatography, reverse-phase HPLC, or isoelectric focusing gel electrophoresis (IEF) (see, e.g., Wakankar et al., 2011, mAbs, 3:161-172).

[0403] Pharmaceutical Composition Compounds of formula (I) and conjugates comprising compounds of formula (I) are generally formulated for therapeutic use. Accordingly, certain embodiments of the present disclosure relate to pharmaceutical compositions comprising a compound of formula (I) or a conjugate thereof, such as a conjugate having formula (X), and a pharmaceutically acceptable carrier, diluent, or excipient. Such pharmaceutical compositions can be prepared by known procedures using well-known and readily available ingredients.

[0404] Pharmaceutical compositions may be formulated for administration to a subject, for example, by oral (e.g., buccal or sublingual), topical, parenteral, rectal, or vaginal routes, or by inhalation or spray. The term parenteral, as used herein, includes subcutaneous injection, and intradermal, intraarticular, intravenous, intramuscular, intravascular, intrasternal, and intrathecal injection or infusion. Pharmaceutical compositions will generally be formulated in a manner suitable for administration to a subject, for example, as syrups, elixirs, tablets, troches, lozenges, hard capsules, soft capsules, pills, suppositories, oily suspensions, aqueous suspensions, dispersible powders, dispersible granules, emulsions, injections, or solutions. Pharmaceutical compositions may be provided as unit-dosage formulations.

[0405] Compositions intended for oral use may be prepared in either solid or liquid unit dosage forms. Fluid unit dosage forms may be prepared according to procedures known in the art for the manufacture of pharmaceutical compositions, and such compositions may contain one or more agents, such as sweeteners, flavoring agents, coloring agents, and preservatives, to provide pharmaceutically elegant and palatable preparations. Elixirs can be prepared by using a hydroalcoholic (e.g., ethanol) carrier with an appropriate sweetener, such as sugar and / or saccharin, along with an aromatic flavoring agent. Suspensions can be prepared using an aqueous carrier and a suspending agent, such as gum arabic, tragacanth, methylcellulose, and the like.

[0406] Solid dosage forms, such as tablets, contain the active ingredient in a mixture with non-toxic pharmaceutically acceptable excipients suitable for tablet manufacture. These excipients may include, for example, inert diluents such as calcium carbonate, sodium carbonate, lactose, calcium phosphate, or sodium phosphate; granulating and disintegrating agents such as cornstarch or alginic acid; binders such as starch, gelatin, or gum arabic, and / or lubricants such as magnesium stearate, stearic acid, or talc, as well as other conventional ingredients such as calcium hydrogen phosphate, magnesium aluminum silicate, calcium sulfate, starch, lactose, methylcellulose, and functionally similar materials. Tablets may be uncoated or may be coated by known techniques, for example, to delay disintegration and absorption in the gastrointestinal tract, thereby providing a sustained action over a longer period. For example, a time-delay material such as glyceryl monostearate or glyceryl distearate may be used.

[0407] The formulation for oral use may also be presented as a hard gelatin capsule, in which the active ingredient is mixed with an inert solid diluent, such as calcium carbonate, calcium phosphate, or kaolin, or as a soft gelatin capsule, in which the active ingredient is mixed with water or an oil medium, such as peanut oil, liquid paraffin, or olive oil.Soft gelatin capsules are generally prepared by machine encapsulation of a slurry of the active ingredient with acceptable vegetable oil, light liquid paraffin, or other inert oil.

[0408] Aqueous suspensions contain the active ingredient in admixture with additives suitable for the manufacture of aqueous suspensions. Such additives include suspending agents such as sodium carboxymethylcellulose, methylcellulose, hydropropylmethylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth, and gum arabic, and dispersing or wetting agents. Dispersing and wetting agents include, for example, naturally occurring phospholipids (e.g., lecithin), condensation products of alkylene oxides and fatty acids (e.g., polyoxyethylene stearate), condensation products of ethylene oxide and long-chain aliphatic alcohols (e.g., heptadecaethyleneoxycetanol), condensation products of ethylene oxide and partial esters derived from fatty acids and hexitols (e.g., polyoxyethylene sorbitol monooleate), or condensation products of ethylene oxide and partial esters derived from fatty acids and hexitol anhydrides (e.g., polyethylene sorbitan monooleate). The aqueous suspensions may also contain one or more preservatives (for example, ethyl, or n-propyl-p-hydroxybenzoate), one or more coloring agents, one or more flavoring agents, and / or one or more sweetening agents (such as sucrose or saccharin).

[0409] Oily suspensions can be prepared by suspending the active ingredient in vegetable oil, such as peanut oil, olive oil, sesame oil, or coconut oil, or in mineral oil such as liquid paraffin.Oily suspensions can contain thickening agents, such as beeswax, hard paraffin, or cetyl alcohol.In order to provide a palatable oral preparation, sweeteners and flavoring agents such as those mentioned above can be added.These suspensions can optionally be protected by adding antioxidants such as ascorbic acid.

[0410] Dispersible powders and granules suitable for preparing an aqueous suspension by adding water generally provide the active ingredient in a mixture with a dispersing or wetting agent, a suspending agent, and one or more preservatives.Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above.One or more additional additives, such as sweeteners, flavoring agents, and / or coloring agents, may also be present.

[0411] The pharmaceutical composition may also be in the form of an oil-in-water emulsion. The oil phase may be a vegetable oil, such as olive oil or peanut oil, or a mineral oil, such as liquid paraffin, or a mixture of such oils. Suitable emulsifiers for inclusion in oil-in-water emulsions include, for example, naturally occurring gums (e.g., acacia gum or tragacanth gum), naturally occurring phospholipids (e.g., soybean, lecithin), or esters or partial esters derived from fatty acids and hexitol anhydrides (e.g., sorbitan monooleate) or condensation products of such partial esters with ethylene oxide (e.g., polyoxyethylene sorbitan monooleate). The emulsion may also optionally contain sweeteners and / or flavoring agents.

[0412] The pharmaceutical compositions may be in the form of a sterile injectable aqueous or oily solution or suspension. Such suspensions can be formulated using suitable dispersing or wetting agents and suspending agents, such as those described above. The sterile injectable solution or suspension may contain the active ingredient in a non-toxic parenterally acceptable carrier or diluent. Acceptable carriers and diluents that can be used include, for example, 1,3-butanediol, water, Ringer's solution, or isotonic sodium chloride solution. Additionally, sterile, fixed oils may be used as carriers. For this purpose, various bland, fixed oils may be used, including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid are also used in the preparation of injectable solutions. Adjuvants such as local anesthetics, preservatives, and / or buffers may also be included in the injectable solution or suspension.

[0413] Pharmaceutical compositions may also be formulated as suppositories for rectal administration. These compositions can be prepared by mixing the active ingredient with a suitable non-irritating excipient that is solid at normal temperatures but liquid at physiological temperatures, thereby melting in the rectum and releasing the drug. Such materials include cocoa butter and polyethylene glycol.

[0414] Other pharmaceutical compositions and methods for preparing pharmaceutical compositions are known in the art and are described, for example, in "Remington: The Science and Practice of Pharmacy" (formerly "Remington's Pharmaceutical Sciences"), Gennaro, A., Lippincott, Williams & Wilkins, Philadelphia, PA (2000).

[0415] How to use Certain embodiments of the present disclosure relate to therapeutic uses of camptothecin analogs of formula (I) and conjugates comprising these compounds, such as conjugates of formula (X). Some embodiments relate to the use of compounds of formula (I) or conjugates of formula (X) as therapeutic agents.

[0416] Because camptothecin analogs of formula (I) exhibit cytotoxic activity against cancer cells, compounds of formula (I) and conjugates comprising these compounds, such as conjugates of formula (X), are useful for inhibiting abnormal cancer or tumor cell growth, inhibiting cancer or tumor cell proliferation, or treating cancer in a patient. In certain embodiments, compounds of formula (I) and conjugates of formula (X) can be used to treat cancer. Accordingly, some embodiments of the present disclosure relate to the use of compounds of formula (I) and conjugates of formula (X) as anticancer agents.

[0417] Certain embodiments of the present disclosure relate to methods of inhibiting the growth of cancer or tumor cells, comprising contacting the cells with a compound of Formula (I) or a conjugate of Formula (X). Some embodiments relate to methods of killing cancer or tumor cells, comprising contacting the cells with a compound of Formula (I) or a conjugate of Formula (X).

[0418] Some embodiments relate to methods of treating a subject with cancer by administering to the subject a compound of Formula (I) or a conjugate of Formula (X). In this context, treatment with a compound of Formula (I) or a conjugate of Formula (X) can result in one or more of: a reduction in tumor size; a delay or prevention of an increase in tumor size; an increase in disease-free survival between the disappearance or removal of a tumor and its reappearance; prevention of subsequent development of a tumor (e.g., metastasis); an increase in time to progression; a reduction in one or more adverse symptoms associated with the tumor; and / or an increase in overall survival of the subject with cancer.

[0419] Certain embodiments relate to the use of a compound of Formula (I) or a conjugate of Formula (X) in a method of inhibiting tumor growth in a subject. Some embodiments relate to the use of a compound of Formula (I) or a conjugate of Formula (X) in a method of inhibiting cancer cell growth and / or killing cancer cells in vitro. Some embodiments relate to the use of a compound of Formula (I) or a conjugate of Formula (X) in a method of inhibiting cancer cell growth and / or killing cancer cells in vivo in a subject with cancer.

[0420] Examples of cancers that may be treated in certain embodiments include hematological tumors, including leukemia, myeloma, and lymphoma, carcinomas, including adenocarcinomas and squamous cell carcinomas, melanomas, and sarcomas. Carcinomas and sarcomas are also often referred to as "solid tumors." Examples of commonly occurring solid tumors that may be treated in certain embodiments include, but are not limited to, brain cancer, breast cancer, cervical cancer, colon cancer, head and neck cancer, kidney cancer, lung cancer, ovarian cancer, pancreatic cancer, prostate cancer, gastric cancer, uterine cancer, non-small cell lung cancer (NSCLC), and colorectal cancer. Various forms of lymphoma can also lead to the formation of solid tumors and, therefore, may also be considered solid tumors in certain circumstances.

[0421] Particular embodiments relate to the use of compounds of formula (I) or conjugates of formula (X) in the treatment of autoimmune diseases such as atopic dermatitis, rheumatoid arthritis, psoriasis or systemic lupus erythematosus.

[0422] Certain embodiments relate to the use of a compound of formula (I) or a conjugate of formula (X) in the treatment of a viral infection, such as an HIV infection or a SARS coronavirus infection.

[0423] Medicine Kit In certain embodiments, a pharmaceutical composition comprising a compound of Formula (I) or a conjugate of Formula (X) may be provided as part of a pharmaceutical kit or pack. Individual components of the kit will generally be packaged in separate containers. Suitable containers include, for example, bottles, blister packs, intravenous solution bags, vials, etc., depending on the formulation of the pharmaceutical composition. In certain embodiments, the container may be in a form that allows for administration to a subject, such as an inhaler, syringe, pipette, eye dropper, pre-soaked gauze or pad, or other device that allows the contents to be administered to a subject.

[0424] The kit may further include a label or package insert on or associated with the container(s). The term "package insert" is used to refer to instructions customarily included in commercial packaging of therapeutic agents, including information about the indications, uses, dosages, administration, contraindications, and / or warnings regarding the use of such therapeutic agents. The label or package insert may further include instructions in a format prescribed by a governmental agency having jurisdiction over the manufacture, use, or sale of pharmaceuticals or biological products, which instructions incorporate approval by the governmental agency for manufacture, use, or sale for human or animal administration. The label or package insert generally indicates that the compound or complex is used to treat a selected condition, e.g., cancer.

[0425] Where appropriate, one or more components of the kit may also be lyophilized or provided in a dried form such as a powder or granules, and the kit may further comprise a suitable solvent for reconstitution of the lyophilized or dried component(s).

[0426] The following examples are offered for illustrative purposes and are not intended to limit the scope of the present invention in any way. [Example]

[0427] Examples 1-3 below illustrate various methods for preparing camptothecin analogs of Formula (I). It is understood that those skilled in the art can produce these compounds by similar methods or by combining other methods known in the art. It is also understood that those skilled in the art can produce other compounds of Formula (I) not specifically shown below using the methods described below or similar methods by using appropriate starting components and modifying the synthetic parameters as needed. In general, starting components can be obtained from commercial sources such as Sigma Aldrich (Merck KGaA), Alfa Aesar and Maybridge (Thermo Fisher Scientific Inc.), Matrix Scientific, Tokyo Chemical Industry Ltd. (TCI), and Fluorochem Ltd., or can be synthesized according to materials known to those skilled in the art (see, for example, March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 7th edition, John Wiley & Sons, Inc., 2013), or can be prepared as described herein.

[0428] Abbreviation The following abbreviations are used throughout the Examples section:

[0429] BCA: bicinchoninic acid, Boc: di-tert-butyl dicarbonate, CE-SDS: capillary electrophoresis sodium dodecyl sulfate, DCM: dichloromethane, DTPA: diethylenetriaminepentaacetic acid, DIPEA: N,N-diisopropylethylamine, DMF: dimethylformamide, DMM™: (4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride, EDC: 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, Fmoc: fluorenylmethyloxycarbonyl, HATU: azabenzotriazole tetramethyluronium hexafluoro Phosphate, HIC: hydrophobic interaction chromatography, HOAt: 1-hydroxy-7-azabenzotriazole, HPLC: high performance liquid chromatography, LCMS: liquid chromatography mass spectrometry, MC: maleimidocaproyl, MT: maleimidotriethylene glycolate, NMM: N-methylmorpholine, PNP: p-nitrophenol, RP-UPLC-MS: reversed-phase ultra-performance liquid chromatography mass spectrometry, SEC: size exclusion chromatography, TCEP: tris(2-carboxyethyl)phosphine, Tfp: tetrafluorophenyl, TLC: thin layer chromatography, TFA: trifluoroacetic acid.

[0430] General Chemistry Procedures General Procedure 1: Conversion of Chlorides to Amine (Synthetic Scheme I; Figure 1A) To a stirred solution of the chloride compound in dimethylformamide (0.05-0.1 M) was added the appropriate secondary amine (3 equiv.). Upon completion (as determined by LCMS, typically 1-3 h), the reaction mixture was purified by reverse-phase HPLC to give the desired product after lyophilization.

[0431] General Procedure 2: Amine to Amide Conversion (Synthetic Scheme II; Figure 1B) To a stirred solution of the amine compound in dimethylformamide (0.05-0.1 M) was added triethylamine (1.2 equiv.), the appropriate carboxylic acid (1.1 equiv.), followed by a solution of DMMTM (2 equiv.) in water (1 M). Upon completion (as determined by LCMS, typically 16 h), the reaction mixture was purified by reverse-phase HPLC to give the desired product after lyophilization.

[0432] General Procedure 3: Conversion of amines to sulfonamides (Synthetic Scheme III; Figure 1C) To a stirred solution of the amine compound in dimethylformamide (0.05-0.1 M) was added DIPEA (3 equiv.), followed by the appropriate sulfonyl chloride. Upon completion (as determined by LCMS, typically 16 h), the reaction mixture was purified by reverse-phase HPLC to give the desired product after lyophilization.

[0433] General Procedure 4: Two-Step Conversion of Amines to Ureas (Synthetic Scheme IV; Figure 1D) Step 1: To a stirred solution (0.05-0.1 M) of the amine compound in dichloromethane or dimethylformamide was added p-nitrophenyl carbonate (1 equivalent), followed by triethylamine (2 equivalents). Upon completion (as determined by LCMS, typically 1-4 hours), the reaction mixture was concentrated to dryness and then purified by reverse-phase HPLC to yield the desired PNP-carbamate intermediate after lyophilization. This intermediate may be used to generate a single analog or may be split into multiple batches to generate multiple analogs in a second step.

[0434] Step 2: To the PNP-carbamate intermediate in dimethylformamide (0.1-0.2 M) was added the appropriate primary amine (3 equivalents). Upon completion (as determined by LCMS, typically 1 h), the reaction mixture was purified by reverse-phase HPLC to give the desired product after lyophilization.

[0435] General Procedure 5: Conversion of amines to carbamates (Synthetic Scheme V; Figure 1E) To a stirred solution of the amine compound in dichloromethane or dimethylformamide (0.05-0.1 M) was added p-nitrophenyl carbonate (1 equivalent), followed by triethylamine (2 equivalents). Upon completion (as determined by LCMS, typically 1-4 hours), the appropriate alcohol was added to the resulting PNP-carbamate intermediate. Upon completion (as determined by LCMS, typically 1-16 hours), the reaction mixture was purified by reverse-phase HPLC to afford the desired product after lyophilization.

[0436] General Procedure 6: Removal of the Boc protecting group To a stirred solution of the Boc-protected amine compound in dichloromethane (0.1 M) was added TFA (20% by volume). Upon completion (as determined by LCMS, typically 1 h), the reaction mixture was concentrated in vacuo to give a crude solid, or purified as described in General Procedure 9.

[0437] General Procedure 7: Copper-Mediated Amide Coupling (Synthetic Scheme VI; Figure 1F) To a rapidly stirred solution (0.02 M) of Boc-GGFG-OH (3 equiv.) and HOAt (3 equiv.) in a 10% v / v mixture of dimethylformamide in dichloromethane was added EDC (HCl salt, 3 equiv.). After 5 min, a solution (0.02 M) of the amine-containing payload (1 equiv.) in a 10% v / v mixture of dimethylformamide in dichloromethane was added, followed immediately by CuCl (4 equiv.). Upon completion (as determined by LCMS, typically 1-16 h), the reaction mixture was concentrated in vacuo to give a crude solid or purified by preparative HPLC to give the desired product after lyophilization.

[0438] General Procedure 8: Incorporation of MTs (Synthetic Scheme VII; Figure 1G) To a stirred solution (approximately 0.02 M) of the amine compound (1 equivalent) in dimethylformamide was added a solution (approximately 0.02 M) of MT-OTfp (1.2-1.5 equivalents) in acetonitrile, followed by DIPEA (10 μL, 4 equivalents). Upon completion (as determined by LCMS, typically 1-16 hours), the reaction mixture was concentrated in vacuo to give a crude solid, which was purified by preparative HPLC to give the desired product after lyophilization.

[0439] General Procedure 9: Compound Purification Flash chromatography: Crude reaction products were purified using Biotage® Snap Ultra columns (10, 25, 50, or 100 g) (Biotage, Charlotte, NC) eluting with a linear gradient of ethyl acetate / hexane or methanol / dichloromethane on a Biotage® Isolera™ automated flash system (Biotage, Charlotte, NC). Alternatively, reverse-phase flash purification was performed using Biotage® Snap Ultra C18 columns (12, 30, 60, or 120 g) eluting with a linear gradient of 0.1% TFA in acetonitrile / 0.1% TFA in water. Purified compounds were isolated either by removal of organic solvents by rotary evaporation or by lyophilization of the acetonitrile / water mixture.

[0440] Preparative HPLC: Reverse-phase HPLC of crude compounds was performed on an Agilent 1260 Infinity II preparative LC / MSD system (Agilent Technologies, Inc., Santa Clara, CA) using a Luna® 5-μm C18 100 Å (150 × 30 mm) column (Phenomenex, Torrance, CA) eluted with a linear gradient of 0.1% TFA in acetonitrile / 0.1% TFA in water. Purified compounds were isolated by lyophilization of the acetonitrile / water mixture.

[0441] General Procedure 10: Compound Analysis LC / MS: Reaction completion was monitored, and purified compounds were analyzed on an Agilent 1290 HPLC / 6120 single quad LC / MS system (Agilent Technologies, Inc., Santa Clara, CA) using a Kinetex® 2.6-μm C18 100 Å (30 × 3 mm) column (Phenomenex, Torrance, CA) eluted with a 10 to 100% linear gradient of 0.1% formic acid in acetonitrile / 0.1% formic acid in water.

[0442] NMR: 1 H NMR spectra were collected using a Bruker AVANCE III 300 Spectrometer (300 MHz) (Bruker Corporation, Billerica, Mass.) Chemical shifts are reported in parts per million (ppm).

[0443] Example 1: Preparation of camptothecin analogs bearing methyl at C10 position 1.1: (S)-11-(chloromethyl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 1.1) [ka] The title compound was prepared according to the procedure set forth in Li, et al., 2019, ACS Med. Chem. Lett., 10(10):1386-1392.

[0444] 1.2: (S)-11-(aminomethyl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 1.2) [ka] The title compound was prepared according to the procedure set forth in Li, et al., 2019, ACS Med. Chem. Lett., 10(10):1386-1392.

[0445] 1.3: (S)-4-Ethyl-8-fluoro-4-hydroxy-9-methyl-11-(morpholinomethyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 100) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and morpholine. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 20 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 3.6 mg, 26% yield).

[0446] LC / MS:C 26 H 26 Calculated m / z for FN3O5 = 479.2, observed [M+H] + =480.4.

[0447] 1 H NMR (300 MHz, CDCl3) δ 8.20 (d, J = 8.0 Hz, 1H), 7.82 (d, J = 10.4 Hz, 1H), 7.67 (s, 1H), 5.77 (d, J = 16.4 Hz, 1H), 5.42 (s, 2H), 5.33 (d, J = 16.4 Hz, 1H), 4.26 (s, 2H), 3.81 (t, J = 4.7 Hz, 4H), 2.82 - 2.76 (m, 4H), 2.57 (d, J = 1.7 Hz, 3H), 1.99 - 1.82 (m, 2H), 1.06 (t, J = 7.4 Hz, 3H).

[0448] 1.4: ((S)-4-Ethyl-8-fluoro-4-hydroxy-9-methyl-11-((4-(phenylsulfonyl)piperazin-1-yl)methyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 102) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and 1-(phenylsulfonyl)piperazine. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 20 to 60% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 3.6 mg, 21% yield).

[0449] LC / MS:C 32 H 31 Calculated m / z for FN4O6 = 618.2, observed [M+H] + =619.4.

[0450] 1 H NMR (300 MHz, CDCl3) δ 8.07 (d, J = 7.9 Hz, 1H), 7.88 - 7.44 (m, 7H), 5.73 (d, J = 16.4 Hz, 1H), 5.33 (s, 2H), 5.33 - 5.26 (m, 1H), 4.19 (s, 2H), 3.12 (s, 4H), 2.80 (s, 4H), 2.54 (s, 3H), 1.90 (dt, J = 11.6, 7.0 Hz, 2H), 1.04 (t, J = 7.3 Hz, 3H).

[0451] 1.5: (S)-11-((4-((4-aminophenyl)sulfonyl)piperazin-1-yl)methyl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 104) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and 4-(piperazin-1-ylsulfonyl)aniline. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 20 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 4.7 mg, 27% yield).

[0452] LC / MS:C 32 H 32 Calculated m / z for FN5O6 = 633.2, found [M+H] + =634.4.

[0453] 1 H NMR (300 MHz, MeOD) δ 8.32 (d, J = 8.0 Hz, 1H), 7.85 (d, J = 10.5 Hz, 1H), 7.65 (s, 1H), 7.46 (d, J = 8.7 Hz, 2H), 6.74 (d, J = 8.7 Hz, 2H), 5.61 (d, J = 16.5 Hz, 1H), 5.44 (s, 2H), 5.41 (d, J = 16.5 Hz, 1H), 4.51 (s, 2H), 3.22 - 3.07 (m, 8H), 2.58 (s, 3H), 2.03 - 1.93 (m, 2H), 1.02 (t, J = 7.3 Hz, 3H).

[0454] 1.6: (S)-4-Ethyl-8-fluoro-4-hydroxy-9-methyl-11-((4-methylpiperazin-1-yl)methyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 106) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and N-methylpiperazine. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 20 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 3.6 mg, 25% yield).

[0455] LC / MS:C 27 H 29 Calculated m / z for FN4O4 = 492.2, found [M+H] + =493.4.

[0456] 1.7: (S)-11-((4-(4-aminophenyl)piperazin-1-yl)methyl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 108) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and 4-(piperazin-1-yl)aniline. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 20 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 3.7 mg, 23% yield).

[0457] LC / MS:C 32 H 32 Calculated m / z for FN5O4 = 569.2, observed [M+H] + =570.4.

[0458] 1H NMR (300 MHz, MeOD) δ 8.39 (d, J = 8.1 Hz, 1H), 7.79 (d, J = 10.6 Hz, 1H), 7.21 (d, J = 9.0 Hz, 2H), 7.14 (d, J = 9.0 Hz, 2H), 5.62 (d, J = 16.4 Hz, 1H), 5.49 (s, 2H), 5.41 (d, J = 16.4 Hz, 1H), 4.45 (s, 2H), 3.44 - 3.38 (m, 4H), 3.06 - 3.00 (m, 4H), 2.58 (d, J = 1.8 Hz, 3H), 2.00 - 1.89 (m, 2H), 1.03 (t, J = 7.3 Hz, 3H).

[0459] 1.8: (S)-4-Ethyl-8-fluoro-4-hydroxy-9-methyl-11-(piperidin-1-ylmethyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 110) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and piperidine. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 1.5 mg, 11% yield).

[0460] LC / MS:C 27 H 28 Calculated m / z for FN3O4 = 477.2, observed [M+H] + =478.2.

[0461] 1H NMR (300 MHz, MeOD) δ 8.34 (d, J = 7.6 Hz, 1H), 7.94 (d, J = 10.3 Hz, 1H), 7.70 (s, 1H), 5.63 (d, J = 16.4 Hz, 1H), 5.52 (s, 2H), 5.44 (d, J = 16.5 Hz, 1H), 4.99 (s, 2H), 3.73 - 3.46 (m, 4H), 2.64 (s, 3H), 2.03 - 1.90 (m, 2H), 1.90 - 1.84 (m, 6H), 1.03 (t, J = 7.4 Hz, 3H).

[0462] 1.9: tert-Butyl (S)-4-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)piperazine-1-carboxylate (compound 111) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and tert-butyl piperazine-1-carboxylate. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 6.6 mg, 40% yield).

[0463] LC / MS:C 31 H 35 Calculated m / z for FN4O6 = 578.2, observed [M+H] + =579.4.

[0464] 1.10: (S)-4-Ethyl-8-fluoro-4-hydroxy-9-methyl-11-(piperazin-1-ylmethyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 112) [ka] The title compound was prepared according to general procedure 6 starting from compound 111 (5.0 mg) to afford the title compound as an off-white solid (TFA salt, 4.4 mg).

[0465] LC / MS:C 26 H 27 Calculated m / z for FN4O4 = 478.2, observed [M+H] + =479.2.

[0466] 1.11: (S)-4-Ethyl-8-fluoro-4-hydroxy-11-(((R)-2-(hydroxymethyl)morpholino)methyl)-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 113) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and (R)-morpholin-2-ylmethanol. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 4.6 mg, 32% yield).

[0467] LC / MS:C 27 H 28 Calculated m / z for FN3O6 = 509.2, found [M+H] + =510.4.

[0468] 1.12: (4S)-4-Ethyl-8-fluoro-4-hydroxy-11-((3-(hydroxymethyl)thiomorpholino)methyl)-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 114) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and thiomorpholin-3-ylmethanol. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 1.5 mg, 12% yield).

[0469] LC / MS:C 27 H 28 Calculated m / z for FN3O5S = 525.6, observed [M+H] + =526.5.

[0470] 1 H NMR (300 MHz, 10%D2O / CD3CN) 8.36 (d, J = 8.1 Hz, 1H), 7.83 (d, J = 10.7 Hz, 1H), 7.50 (s, 1H), 5.57 (d, J = 16.4 Hz, 1H), 5.52 - 5.29 (m, 3H), 5.02 (d, J = 14.6 Hz, 1H), 4.71 - 4.54 (m, 1H), 4.27 (dd, J = 12.4, 5.0 Hz, 1H), 3.98 (dd, J = 12.3, 3.4 Hz, 1H), 3.55 (s, 1H), 3.30-3.03 (m, 4H) 2.97 - 2.72 (m, 3H), 2.62 (s, 1H), 2.55 (s, 3H), 0.95 (t, J = 7.4 Hz, 3H).

[0471] 1.13: (4S)-4-Ethyl-8-fluoro-4-hydroxy-11-((4-(hydroxymethyl)-2-oxa-5-azabicyclo[2.2.1]heptan-5-yl)methyl)-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 115) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and 2-oxa-5-azabicyclo[2.2.1]heptan-4-ylmethanol. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 3.5 mg, 29% yield).

[0472] LC / MS:C 28 H 28 Calculated m / z for FN3O6 = 521.5, observed [M+H] + =522.5.

[0473] 1 H NMR (300 MHz, 10%D2O / CD3CN) δ 8.36 (d, J = 7.9 Hz, 1H), 7.86 (dd, J = 10.6, 5.0 Hz, 1H), 7.50 (d, J = 1.8 Hz, 1H), 5.63 - 5.49 (m, 2H), 5.37 (dd, J = 17.8, 14.1 Hz, 2H), 5.05 (s, 2H), 4.63 (d, J = 2.5 Hz, 1H), 4.55 (d, J = 10.7 Hz, 1H), 4.33 (s, 2H), 3.92 (d, J = 10.7 Hz, 1H), 3.36 (s, 2H), 2.57 (s, 3H), 2.41 - 2.13 (m, 2H), 1.97-1.85 (m, 2H), 0.95 (t, J = 7.4 Hz, 3H).

[0474] 1.14: (4S)-4-Ethyl-8-fluoro-4-hydroxy-11-((3-(hydroxymethyl)-1,1-dioxidethiomorpholino)methyl)-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 116) [ka] The title compound was prepared by dissolving compound 1.1 (10 mg) and 3-(hydroxymethyl)-1.1. 6 Prepared according to general procedure 1 starting from -thiomorpholine-1,1-dione. Purification was carried out as described in general procedure 9, eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 0.2 mg, 2% yield).

[0475] LC / MS:C 27 H 28 Calculated m / z for FN3O7S = 557.6, found [M+H] + =558.4.

[0476] 1 H NMR (300 MHz, 10% D2O / CD3CN) δ 8.44 (d, J = 8.2 Hz, 1H), 7.80 (d, J = 11.0 Hz, 1H), 7.50 (s, 1H), 5.58 (d, J = 16.5 Hz, 1H), 5.45 - 5.26 (m, 3H), 4.60 (d, J = 14.9 Hz, 1H), 4.33 (d, J = 14.7 Hz, 1H), 3.88 (d, J = 4.8 Hz, 2H), 3.41-2.85 (m, 4H), 2.53 (s, 2H), 2.19 (p, J = 2.5 Hz, 2H), 1.74 (p, J = 2.5 Hz, 2H), 1.27 (s, 2H), 0.95 (t, J = 7.4 Hz, 3H).

[0477] 1.15: (4S)-4-Ethyl-8-fluoro-4-hydroxy-11-((6-hydroxy-3-azabicyclo[3.1.1]heptan-3-yl)methyl)-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 117) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and 3-azabicyclo[3.1.1]heptan-6-ol. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 1.3 mg, 11% yield).

[0478] LC / MS:C 28 H 28 Calculated m / z for FN3O5 = 505.5, observed [M+H] + =506.6.

[0479] 1 H NMR (300 MHz, 10% D2O / CD3CN) δ 8.25 (d, J = 7.9 Hz, 1H), 7.87 (d, J = 10.6 Hz, 1H), 7.50 (s, 1H), 5.65 - 5.27 (m, 4H), 4.98 (s, 2H), 4.24 (s, 1H), 3.83 - 3.57 (m, 4H), 2.54 (s, 5H), 2.01-1.86 (m, 2H), 1.70 (s, 2H), 0.95 (t, J = 7.3 Hz, 3H).

[0480] 1.16: (S)-4-Ethyl-8-fluoro-11-((3-fluoro-3-(hydroxymethyl)azetidin-1-yl)methyl)-4-hydroxy-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 118) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and 3-fluoroazetidin-3-ylmethanol. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 10 to 60% CHCN / HO+0.1% TFA gradient, to afford the title compound as an off-white solid (TFA salt, 1.4 mg, 12% yield).

[0481] LC / MS:C 26 H 25 Calculated m / z for F2N3O5 = 497.5, observed [M+H] + =498.4.

[0482] 1 H NMR (300 MHz, 10% D2O / CD3CN) δ 8.24 (d, J = 7.9 Hz, 1H), 7.85 (d, J = 10.7 Hz, 1H), 7.50 (s, 1H), 5.57 (d, J = 16.5 Hz, 1H), 5.48 - 5.28 (m, 3H), 4.98 (s, 2H), 4.44 - 4.14 (m, 4H), 3.78 (d, J = 14.9 Hz, 2H), 2.01-1.86 (m, 2H), 0.95 (t, J = 7.4 Hz, 3H).

[0483] 1.17: (S)-4-Ethyl-8-fluoro-4-hydroxy-11-((3-(hydroxymethyl)azetidin-1-yl)methyl)-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 119) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and azetidin-3-ylmethanol. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 60% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 0.5 mg, 4.5% yield).

[0484] LC / MS:C 26 H 26 Calculated m / z for FN3O5 = 479.5, observed [M+H] + =480.4.

[0485] 1 H NMR (300 MHz, 10% D2O / CD3CN) δ 8.23 ​​(d, J = 7.8 Hz, 1H), 7.90 (d, J = 10.6 Hz, 1H), 7.53 (s, 1H), 5.58 (d, J = 16.5 Hz, 1H), 5.50 - 5.28 (m, 3H), 5.01 (s, 2H), 4.31 - 4.17 (m, 2H), 4.15 - 4.00 (m, 2H), 3.62 (d, J = 3.9 Hz, 2H), 2.58 (s, 3H), 2.01-1.86 (m, 2H), 0.96 (t, J = 7.4 Hz, 3H).

[0486] 1.18: (4S)-11-((4,4-difluoro-3-(hydroxymethyl)piperidin-1-yl)methyl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 120) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and 4,4-difluoropiperidin-3-ylmethanol. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 10 to 60% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 4 mg, 32% yield).

[0487] LC / MS:C 28 H 28 Calculated m / z for F3N3O5 = 543.5, observed [M+H] +=544.4.

[0488] 1 H NMR (300 MHz, 10% D2O / CD3CN) δ 8.25 (d, J = 8.0 Hz, 1H), 7.77 (dd, J = 10.7, 1.4 Hz, 1H), 7.47 (s, 1H), 5.55 (d, J = 16.5 Hz, 1H), 5.42 - 5.25 (m, 3H), 4.66 (d, J = 3.2 Hz, 2H), 3.90 - 3.77 (m, 1H), 3.71 - 3.45 (m, 4H), 2.24 (q, J = 11.8, 9.2 Hz, 2H), 2.01-1.86 (m, 2H), 0.94 (t, J = 7.4 Hz, 3H).

[0489] 1.19: (S)-4-Ethyl-8-fluoro-4-hydroxy-11-((1-(hydroxymethyl)-7-azabicyclo[2.2.1]heptan-7-yl)methyl)-9-methyl-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 121) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (10 mg) and 7-azabicyclo[2.2.1]heptan-1-ylmethanol. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient, to afford the title compound as an off-white solid (TFA salt, 0.8 mg, 6.6% yield).

[0490] LC / MS:C 29 H 30 Calculated m / z for FN3O5 = 519.6, observed [M+H] + =520.4.

[0491] 1H NMR (300 MHz, 10% D2O / CD3CN) δ 8.22 (s, 1H), 7.92 (d, J = 10.7 Hz, 1H), 7.54 (s, 1H), 5.59 (dd, J = 17.6, 7.6 Hz, 2H), 5.33 (t, J = 17.4 Hz, 2H), 4.98 - 4.81 (m, 1H), 4.67 - 4.44 (m, 2H), 4.28 - 3.93 (m, 4H), 2.73 (s, 2H), 2.34 - 2.03 (m, 4H), 1.91 (d, J = 14.0 Hz, 5H), 0.96 (t, J = 7.4 Hz, 3H).

[0492] 1.20: (S)-N-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)methanesulfonamide (compound 122) [ka] The title compound was prepared according to general procedure 3 starting from compound 1.2 (10 mg) and methanesulfonyl chloride. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 50% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (0.8 mg, 7% yield).

[0493] LC / MS:C 23 H 22 Calculated m / z for FN3O6S = 487.1, observed [M+H] + =488.2.

[0494] 1H NMR (300 MHz, MeOD) δ 8.33 (d, J = 8.1 Hz, 1H), 7.83 (d, J = 10.8 Hz, 1H), 7.68 (s, 1H), 5.62 (d, J = 16.3 Hz, 1H), 5.52 (s, 2H), 5.42 (d, J = 16.4 Hz, 1H), 4.87 (s, 2H), 3.06 (s, 3H), 2.59 (s, 3H), 2.06-1.93 (m, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0495] 1.21: (S)-N-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-1-(4-nitrophenyl)methanesulfonamide (compound 124) [ka] The title compound was prepared according to general procedure 3 starting from compound 1.2 (20 mg) and (4-nitrophenyl)methanesulfonyl chloride. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 10 to 50% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (5.0 mg, 17% yield).

[0496] LC / MS:C 29 H 25 Calculated m / z for FN4O8S = 608.1, observed [M+H] + =609.2.

[0497] 1H NMR (300 MHz, CDCl3) δ 8.02 - 7.92 (m, 3H), 7.74 (d, J = 10.5 Hz, 1H), 7.65 (s, 1H), 7.33 (d, J = 8.6 Hz, 2H), 5.66 (d, J = 16.8 Hz, 1H), 5.28 (d, J = 16.5 Hz, 1H), 5.14 (d, J = 5.4 Hz, 2H), 4.67 (s, 2H), 4.28 (d, J = 6.3 Hz, 2H), 3.39 (s, 3H), 2.03 - 1.83 (m, 2H), 1.04 (t, J = 7.4 Hz, 3H).

[0498] 1.22: (S)-N-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)benzenesulfonamide (compound 125) [ka] The title compound was prepared according to general procedure 3 starting from compound 1.2 (10 mg) and benzenesulfonyl chloride. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 10 to 50% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (9.8 mg, 73% yield).

[0499] LC / MS:C 28 H 24 Calculated m / z for FN3O6S = 549.6, observed [M+H] + =550.6.

[0500] 1H NMR (300 MHz, DMSO-d6) δ 8.60 (t, J = 6.2 Hz, 1H), 8.17 (d, J = 8.1 Hz, 1H), 7.83 (d, J = 10.8 Hz, 1H), 7.71 (dd, J = 7.1, 1.7 Hz, 2H), 7.66 - 7.48 (m, 2H), 7.46 (dd, J = 8.3, 6.8 Hz, 2H), 7.40 - 7.27 (m, 2H), 7.18 (s, 1H), 7.01 (s, 1H), 5.45 (s, 2H), 5.33 (s, 2H), 4.63 (d, J = 6.2 Hz, 2H), 2.48 (s, 3H), 1.98 - 1.76 (m, 2H), 0.89 (t, J = 7.3 Hz, 3H).

[0501] 1.23: (S)-N-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-4-nitrobenzenesulfonamide (compound 1.23) [ka] The title compound was prepared according to general procedure 3 starting from compound 1.2 (75 mg) and 4-nitrobenzenesulfonyl chloride. Purification of the title compound was carried out as described in general procedure 9 using a 12 g C18 column eluted with a 5 to 75% CH3CN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (37.8 mg, 47% yield).

[0502] LC / MS:C 28 H 23 Calculated m / z for FN4O8S = 594.6, observed [M+H] + =595.2.

[0503] 1.24: (S)-4-amino-N-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)benzenesulfonamide (compound 127) [ka] To a solution of compound 1.23 (37.8 mg, 0.064 mmol) in methanol (6.4 mL) was added platinum 1% vanadium 2% carbon (75 mg). The flask was purged with H and then stirred under an H atmosphere at room temperature for 45 minutes. The mixture was filtered through a pad of Celite, washed with DMF, and the filtrate was evaporated to give the title compound as a pale yellow solid (30 mg, 84% yield).

[0504] LC / MS:C 28 H 24 Calculated m / z for FN4O6S = 564.6, observed [M+H] + =565.2.

[0505] 1 H NMR (300 MHz, DMSO-d6) δ 8.13 (d, J = 8.2 Hz, 1H), 8.02 (t, J = 6.2 Hz, 1H), 7.88 (d, J = 10.8 Hz, 1H), 7.48 - 7.35 (m, 2H), 7.31 (d, J = 8.4 Hz, 1H), 6.63 - 6.45 (m, 2H), 5.45 (s, 2H), 5.36 (s, 2H), 4.50 (d, J = 6.3 Hz, 2H), 1.98 - 1.75 (m, 2H), 0.89 (t, J = 7.3 Hz, 3H).

[0506] 1.25: (S)-N-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-2-hydroxyethane-1-sulfonamide (compound 129) [ka] The title compound was prepared according to general procedure 3 starting from compound 1.2 (20 mg) and 2-hydroxyethanesulfonyl chloride. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 25 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (1.3 mg, 13% yield).

[0507] LC / MS:C 24 H 24 Calculated m / z for FN3O7S = 517.1, observed [M+H] + =518.2.

[0508] 1 H NMR (300 MHz, DMSO-d6) δ 8.30 (d, J = 8.4 Hz, 1H), 7.91 (d, J = 10.9 Hz, 1H), 7.84 (t, J = 6.3 Hz, 1H), 7.33 (s, 1H), 5.50-5.33 (m, 4H), 5.07 (t, J = 5.4 Hz, 1H), 4.78 (d, J = 6.0 Hz, 2H), 4.07 (s, 3H), 3.80 (dt, J = 6.3 Hz, J = 5.8 Hz, 2H), 1.86 (m, 2H), 0.87 (d, J = 7.3 Hz, 3H).

[0509] 1.26: (S)-N-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)methanesulfamide (Compound 131) [ka] To a solution of chlorosulfonyl isocyanate (3 uL) in dichloromethane (1 mL) was added tert-butanol (3 uL). This solution was stirred for 1 hour, after which compound 1.2 (13 mg) dissolved in dichloromethane (1 mL) was added, followed by triethylamine (13 uL). The reaction was stirred for 1 hour and then concentrated to dryness. Preparative HPLC purification of the intermediate Boc compound was performed as described in General Procedure 9, eluting with a 10-50% CH3CN / HO + 0.1% TFA gradient. To the purified solid in dichloromethane (1 mL) was added trifluoroacetic acid (200 uL). The reaction was stirred for 16 hours and then concentrated to dryness to give the title compound as an off-white solid (7.5 mg, 48% yield).

[0510] LC / MS:C 22 H 21 Calculated m / z for FN4O6S = 488.1, observed [M+H] + =489.0.

[0511] 1 H NMR (300 MHz, MeOD) δ 8.25 (d, J = 8.1 Hz, 1H), 7.73 (d, J = 10.7 Hz, 1H), 7.62 (s, 1H), 5.59 (d, J = 16.4 Hz, 1H), 5.45 (s, 2H), 5.39 (d, J = 16.4 Hz, 1H), 4.81 (s, 2H), 2.55 (d, J = 1.7 Hz, 3H), 2.07 - 1.89 (m, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0512] 1.27: 4-Nitrophenyl-(S)-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamate (compound 1.27) [ka] The title PNP-carbamate intermediate compound was prepared according to step 1 of general procedure 4 starting from compound 1.2 (24 mg). Flash purification was performed as described in general procedure 9 using a 12 g C18 column eluting with a 10 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (14 mg, 53% yield).

[0513] LC / MS:C 29 H 23 Calculated m / z for FN4O8S = 574.2, observed [M+H] + =575.2.

[0514] 1.28: (S)-1-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-3-methylurea (compound 132) [ka] The title compound was prepared according to general procedure 4 using compound 1.2 (25 mg) and aqueous methylamine (500 μL, 40 wt % in water) as the primary amine. In this case, the intermediate PNP-carbamate was used crude. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 10 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (8.9 mg, 31% yield).

[0515] LC / MS:C 24 H 23 Calculated m / z for FN4O5 = 466.2, observed [M+H] + =467.2.

[0516] 1H NMR (300 MHz, MeOD) δ 8.26 (d, J = 8.2 Hz, 1H), 7.79 (d, J = 10.7 Hz, 1H), 7.66 (s, 1H), 5.61 (d, J = 16.3 Hz, 1H), 5.48 (s, 2H), 5.41 (d, J = 16.4 Hz, 1H), 4.97 (s, 2H), 2.73 (s, 3H), 2.57 (s, 3H), 2.08 - 1.93 (m, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0517] 1.29: (S)-1-(4-aminobenzyl)-3-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)urea (compound 134) [ka] The title compound was prepared according to General Procedure 4, Step 2, using compound 1.27 (4 mg) as the PNP-carbamate and 4-(aminomethyl)aniline as the primary amine. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 20 to 50% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (0.6 mg, 12% yield).

[0518] LC / MS:C 30 H 28 Calculated m / z for FN5O5 = 557.2, found [M+H] + =558.4.

[0519] 1H NMR (300 MHz, MeOD) δ 8.25 (d, J = 8.1 Hz, 1H), 7.80 (d, J = 10.8 Hz, 1H), 7.67 (s, 1H), 7.43 (d, J = 8.2 Hz, 2H), 7.24 (d, J = 8.3 Hz, 2H), 5.63 (d, J = 16.4 Hz, 1H), 5.48 (s, 2H), 5.43 (d, J = 16.4 Hz, 1H), 5.01 (s, 2H), 4.37 (s, 2H), 2.56 (d, J = 1.7 Hz, 3H), 2.05 - 1.94 (m, 2H), 1.03 (t, J = 7.3 Hz, 3H).

[0520] 1.30: (S)-1-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-3-(2-hydroxyethyl)urea (compound 136) [ka] The title compound was prepared according to General Procedure 4, Step 1, using compound 1.27 (4 mg) as the PNP-carbamate and hydroxyethylamine as the primary amine. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 10 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (2.4 mg, 66% yield).

[0521] LC / MS:C 25 H 25 Calculated m / z for FN4O6 = 496.2, observed [M+H] + =497.2.

[0522] 1H NMR (300 MHz, MeOD) δ 8.08 (d, J = 8.0 Hz, 1H), 7.74 (d, J = 10.5 Hz, 1H), 7.68 (s, 1H), 5.64 (d, J = 16.4 Hz, 1H), 5.41 (s, 2H), 5.31 (d, J = 16.4 Hz, 1H), 4.96 (s, 2H), 3.63 (t, J = 5.2 Hz, 2H), 3.29 (t, J = 5.3 Hz, 2H), 2.54 (s, 3H), 1.98 - 1.87 (m, 2H), 1.01 (t, J = 7.4 Hz, 3H).

[0523] 1.31: Methyl-(S)-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamate (compound 138) [ka] The title compound was prepared according to general procedure 5, starting from compound 1.2 (50 mg) and reacting methanol with the intermediate PNP-carbamate. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 20 to 50% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (3.5 mg, 6% yield).

[0524] LC / MS:C 24 H 22 Calculated m / z for FN3O6 = 467.2, observed [M+H] + =468.2.

[0525] 1H NMR (300 MHz, MeOD) δ 8.17 (d, J = 8.2 Hz, 1H), 7.77 (d, J = 10.5 Hz, 1H), 7.69 (s, 1H), 5.65 (d, J = 16.5 Hz, 1H), 5.48 (s, 2H), 5.33 (d, J = 16.4 Hz, 1H), 4.86 (d, J = 5.6 Hz, 2H), 3.65 (s, 3H), 2.56 (s, 3H), 2.02 - 1.89 (m, 2H), 1.02 (t, J = 7.4 Hz, 3H).

[0526] 1.32: 2-Hydroxyethyl (S)-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamate (compound 139) [ka] The title compound was prepared according to general procedure 5, starting from compound 1.2 (18 mg) by reacting 1,2-ethanediol with the intermediate PNP-carbamate. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 10 to 60% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (4.2 mg, 19% yield).

[0527] LC / MS:C 25 H 24 Calculated m / z for FN3O7 = 497.2, observed [M+H] + =498.2.

[0528] 1H NMR (300 MHz, DMSO) δ 8.23 ​​(d, J = 8.2 Hz, 1H), 7.78 (d, J = 10.7 Hz, 1H), 7.40 (s, 1H), 5.47 (d, J = 16.5 Hz, 1H), 5.42 (s, 2H), 5.34 (d, J = 16.4 Hz, 1H), 4.77 (s, 2H), 3.99 (t, J = 4.9 Hz, 2H), 3.64 - 3.38 (m, 2H), 2.48 (s, 3H), 2.02 - 1.67 (m, 2H), 0.89 (t, J = 7.3 Hz, 3H).

[0529] Example 2: Preparation of camptothecin analogs with methoxy at C10 position 2.1: 1-(2-amino-4-fluoro-5-methoxyphenyl)-2-chloroethan-1-one (compound 2.1) [ka] A solution of 3-fluoro-4-methoxyaniline (10 g, 71 mmol) in DCM (100 mL) was cooled to 0 °C. To this solution was added first 1 M BCl in DCM (71 mL, 71 mmol), followed by 1 M chloro(diethyl)almane in DCM (71 mL, 71 mmol), and finally 2-chloroacetonitrile (6.4 g, 85 mmol). The solution was heated at reflux for 3 h, cooled to room temperature, and quenched by the addition of 2 M aqueous HCl. The resulting heterogeneous mixture was heated at reflux for 1 h, cooled to room temperature, and then the pH was adjusted to approximately 12 with NaCO. The layers were separated, and the aqueous layer was extracted with DCM (3 × 100 mL). The combined organic layers were dried over Na2SO4, concentrated, and flash purified as described in general procedure 9, eluting with 0 to 20% EtOAc / hexanes, to give the title compound (6 g, 28 mmol, 39% yield).

[0530] LC / MS: m / z calculated for C9H9ClFNO2 = 217.1, found [M+H] + =218.1.

[0531] 1 H NMR (400 MHz, CDCl3) δ 7.19 (d, J = 9.2 Hz, 1H), 6.44 (d, J = 12.8 Hz, 1H), 4.59 (s, 2H), 3.86 (s, 3H).

[0532] 2.2: (S)-11-(chloromethyl)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 2.2) [ka] To a solution of compound 2.1 (1.65 g, 7.6 mmol) and (S)-4-ethyl-4-hydroxy-7,8-dihydro-1H-pyrano[3,4-f]indolizine-3,6,10(4H)-trione (2 g, 7.6 mmol) in toluene (200 mL) was added toluene-4-sulfonic acid (157 mg, 0.9 mmol). The solution was heated at 140 °C for 3 h and then cooled to room temperature. The product was collected by filtration as a yellow precipitate to give the title compound (1.27 g, 2.85 mmol, 37.5% yield).

[0533] LC / MS:C 22 H 18 Calculated m / z for ClFN2O5 = 445.2, found [M+H] + =445.1.

[0534] 1 H NMR (400 MHz, DMSO-d6) δ 7.99 (d, J =12.0 Hz, 1H) 7.80 (d, J = 9.2 Hz, 1H) 7.27 (s, 1H), 6.50 (s, 1H), 5.45 (s, 2H), 5.41 (s, 2H), 5.33 (s, 2H) 4.08 (s, 3H), 1.87 - 1.83 (m, 2H), 0.87 (t, J = 7.2 Hz, 3H).

[0535] 2.3: (S)-4-Ethyl-8-fluoro-4-hydroxy-9-methoxy-11-(morpholinomethyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 101) [ka] The title compound was prepared according to general procedure 1 starting from compound 2.2 (10 mg) and morpholine. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 20 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (5.6 mg, 41% yield).

[0536] LC / MS:C 26 H 26 Calculated m / z for FN3O6 = 495.2, observed [M+H] + =496.4.

[0537] 1 H NMR (300 MHz, MeOD) δ 7.84 - 7.70 (m, 2H), 7.59 (s, 1H), 5.62 (d, J = 16.3 Hz, 1H), 5.45 - 5.36 (m, 3H), 4.29 (s, 2H), 4.12 (s, 3H), 3.58 - 3.48 (m, 2H), 3.28 - 3.09 (m, 2H), 2.75 - 2.61 (m, 2H), 2.05 - 1.91 (m, 2H), 1.02 (t, J = 7.4 Hz, 3H).

[0538] 2.4: (S)-4-Ethyl-8-fluoro-4-hydroxy-9-methoxy-11-((4-(phenylsulfonyl)piperazin-1-yl)methyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 103) [ka] The title compound was prepared according to general procedure 1 starting from compound 2.2 (10 mg) and 1-(phenylsulfonyl)piperazine. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 20 to 60% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (2.5 mg, 14% yield).

[0539] LC / MS:C 32 H 31 Calculated m / z for FN4O7S = 634.2, observed [M+H] + =635.4.

[0540] 2.5: (S)-11-((4-((4-aminophenyl)sulfonyl)piperazin-1-yl)methyl)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 105) [ka] The title compound was prepared according to general procedure 1 starting from compound 2.2 (10 mg) and 4-(piperazin-1-ylsulfonyl)aniline. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 20 to 60% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (4.0 mg, 23% yield).

[0541] LC / MS:C 32 H 32 Calculated m / z for FN5O7S = 649.2, observed [M+H] + =650.4.

[0542] 1H NMR (300 MHz, DMSO) δ 8.08 (s, 2H), 7.90 - 7.67 (m, 2H), 7.35 (s, 1H), 7.32 - 7.26 (m, 2H), 6.67 - 6.57 (m, 2H), 5.46 (d, J = 16.5 Hz, 1H), 5.33 -5.22 (m, 3H), 3.92 (s, 3H), 3.02 - 2.72 (m, 4H), 2.75 - 2.58 (m, 4H), 1.97 - 1.70 (m, 2H), 0.90 (t, J = 7.3 Hz, 3H).

[0543] 2.6: (S)-4-Ethyl-8-fluoro-4-hydroxy-9-methoxy-11-((4-methylpiperazin-1-yl)methyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 107) [ka] The title compound was prepared according to general procedure 1 starting from compound 2.2 (10 mg) and N-methylpiperazine. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 20 to 60% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (2.1 mg, 19% yield).

[0544] LC / MS:C 27 H 29 Calculated m / z for FN4O5 = 508.2, observed [M+H] + =509.4.

[0545] 2.7: (S)-11-((4-(4-aminophenyl)piperazin-1-yl)methyl)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 109) [ka] The title compound was prepared according to general procedure 1 starting from compound 2.2 (10 mg) and 4-(piperazin-1-yl)aniline. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 20 to 60% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (3.2 mg, 20% yield).

[0546] LC / MS:C 32 H 32 Calculated m / z for FN5O5 = 585.2, observed [M+H] + =586.4.

[0547] 1 H NMR (300 MHz, MeOD) δ 7.83 - 7.74 (m, 2H), 7.62 (s, 1H), 7.06 (d, J = 8.9 Hz, 2H), 6.98 (d, J = 8.9 Hz, 2H), 5.65 (d, J = 16.4 Hz, 1H), 5.36 (s, 2H), 5.27 (d, J = 16.4 Hz, 1H), 4.13 (s, 2H), 4.06 (s, 3H), 3.26 (br s, 4H), 2.79 (br s, 4H), 1.97 - 1.83 (m, 2H), 1.00 (t, J = 7.4 Hz, 3H).

[0548] 2.8: (S)-11-(aminomethyl)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 2.8) [ka] To a solution of compound 2.2 (250 mg, 0.56 mmol) in ethanol (7 mL) was added hexamethylenetetramine (236 mg, 1.7 mmol), followed by iPrNEt (100 μL, 0.56 mmol). The solution was heated to reflux for 5 h, cooled to room temperature, and quenched with 12 M aqueous HCl (60 μL). The solution was concentrated to approximately half its volume, and 1 M aqueous HCl (1.5 mL) was added, stirred for 5 min, and then concentrated to give a brown residue. Purification was carried out as described in General Procedure 9 using a 12 g C18 flash column eluting with a 5 to 40% CH3CN / HO + 0.1% TFA gradient to give the title compound as a pale yellow solid (179 mg, 75% yield).

[0549] LC / MS:C 22 H 20 Calculated m / z for FN3O5 = 425.4, observed [M+H] + =426.2.

[0550] 2.9: (S)-N-((4-ethyl-8-fluoro-4-hydroxy-9-methoxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)methanesulfonamide (compound 123) [ka] The title compound was prepared according to general procedure 3 starting from compound 2.8 (10 mg) and methanesulfonyl chloride. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 5 to 65% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (8.5 mg, 91% yield).

[0551] LC / MS:C 23 H 22 Calculated m / z for FN3O7S = 503.1, observed [M+H] + =504.2.

[0552] 1H NMR (300 MHz, DMSO-d6) δ 7.98 (d, J = 12.1 Hz, 1H), 7.89 (t, J = 6.4 Hz, 1H), 7.80 (d, J = 9.1 Hz, 1H), 7.28 (s, 1H), 5.42 (s, 2H), 5.39 (s, 2H), 4.77 (d, J = 6.4 Hz, 2H), 4.06 (s, 3H), 3.06 (s, 3H), 1.95-1.73 (m, 2H), 0.88 (d, J = 7.3 Hz, 3H).

[0553] 2.10: (S)-N-((4-ethyl-8-fluoro-4-hydroxy-9-methoxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)benzenesulfonamide (compound 126) [ka] The title compound was prepared according to general procedure 3 starting from compound 2.8 (7.5 mg) and benzenesulfonyl chloride. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 5 to 70% CHCN / HO+0.1% TFA gradient to afford the title compound as an off-white solid (4.6 mg, 46% yield).

[0554] LC / MS:C 28 H 24 Calculated m / z for FN3O7S = 565.6, observed [M+H] + =566.2.

[0555] 1H NMR (300 MHz, DMSO-d6) δ 8.59 (t, J = 6.3 Hz, 1H), 7.94 (d, J = 12.2 Hz, 1H), 7.82 - 7.68 (m, 2H), 7.62 - 7.46 (m, 1H), 7.51 - 7.40 (m, 1H), 7.28 (d, J = 8.3 Hz, 1H), 6.52 (s, 1H), 5.44 (s, 1H), 5.36 (s, 1H), 4.64 (d, J = 6.3 Hz, 1H), 4.09 (s, 2H), 1.95 - 1.81 (m, 1H), 0.89 (t, J = 7.3 Hz, 2H).

[0556] 2.11: (S)-N-((4-ethyl-8-fluoro-4-hydroxy-9-methoxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-4-nitrobenzenesulfonamide (compound 2.11) [ka] The title compound was prepared according to general procedure 3 starting from compound 2.8 (12 mg) and 4-nitrobenzenesulfonyl chloride. Purification was carried out as described in general procedure 9 using a 12 g C18 flash column eluted with a 5 to 75% CH3CN / HO+0.1% TFA gradient to afford the title compound as a pale yellow solid (9.7 mg, 71% yield).

[0557] LC / MS:C 28 H 23 Calculated m / z for FN4O9S = 610.6, observed [M+H] + =611.5.

[0558] 2.12: (S)-4-amino-N-((4-ethyl-8-fluoro-4-hydroxy-9-methoxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)benzenesulfonamide (compound 128) [ka] To a solution of compound 2.11 (9.7 mg, 0.016 mmol) in methanol (1.6 mL) was added platinum 1% vanadium 2% carbon (15 mg). The flask was purged with H and then stirred under an H atmosphere at room temperature for 45 minutes. The mixture was filtered through a pad of Celite, washed with DMF, and the filtrate was evaporated to give the title compound as a pale yellow solid (1.5 mg, 16% yield).

[0559] LC / MS:C 28 H 25 Calculated m / z for FN4O7S = 580.6, observed [M+H] + =581.4.

[0560] 1 H NMR (300 MHz, MeOD) δ 7.77 (d, J = 11.0 Hz, 1H), 7.58 (s, 1H), 7.48 (d, J = 8.6 Hz, 1H), 6.61 (d, J = 8.6 Hz, 1H), 5.59 (d, J = 16.3 Hz, 1H), 5.39 (d, J = 16.4 Hz, 1H), 5.30 (s, 1H), 4.56 (s, 1H), 4.10 (d, J = 3.7 Hz, 3H), 2.04 - 1.91 (m, 2H), 1.31 (s, 1H), 1.02 (t, J = 7.3Hz, 3H), 0.90 (s, 1H).

[0561] 2.13: (S)-N-((4-ethyl-8-fluoro-4-hydroxy-9-methoxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-2-hydroxyethane-1-sulfonamide (compound 130) [ka] The title compound was prepared according to general procedure 3 starting from compound 2.8 (8 mg) and 2-hydroxyethanesulfonyl chloride. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 15 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (2.2 mg, 22% yield).

[0562] LC / MS:C 24 H 24 Calculated m / z for FN3O8S = 533.1, observed [M+H] + =534.2.

[0563] 1 H NMR (300 MHz, DMSO-d6) δ 7.99 (d, J = 12.2 Hz, 1H), 7.89-7.79 (m, 2H), 7.29 (s, 1H), 5.43 (s, 2H), 5.40 (s, 2H), 4.76 (d, J = 6.4 Hz, 2H), 4.06 (s, 3H), 3.81 (t, J = 6.3 Hz, 2H), 3.34 (t, J = 6.3 Hz, 2H), 1.94-1.75 (m, 2H), 0.87 (d, J = 7.4 Hz, 3H).

[0564] 2.14: 4-Nitrophenyl-(S)-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamate (compound 2.14) [ka] The title PNP-carbamate intermediate compound was prepared according to step 1 of general procedure 4, starting from compound 2.8 (65 mg) and using a 1:1 mixture of dimethylformamide and dichloromethane as the solvent. Flash purification was performed as described in general procedure 9 using a 12 g C12 column eluted with a 10 to 50% CH3CN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (61 mg, 86% yield). This intermediate was resolved and used to generate the next compound.

[0565] LC / MS:C 29 H 23 Calculated m / z for FN4O9 = 590.1, observed [M+H] + =591.2.

[0566] 2.15: (S)-1-((4-ethyl-8-fluoro-4-hydroxy-9-methoxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-3-methylurea (compound 133) [ka] The title compound was prepared according to General Procedure 4, Step 2, using compound 2.14 (15 mg) as the PNP-carbamate and aqueous methylamine (500 uL, 40 wt % in water) as the primary amine. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 20 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (5.8 mg, 47% yield).

[0567] LC / MS:C 24 H 23 Calculated m / z for FN4O6 = 482.2, observed [M+H] + =483.2.

[0568] 1H NMR (300 MHz, DMSO-d6) δ 8.00 - 7.87 (m, 2H), 7.31 (s, 1H), 5.48 - 5.39 (m, 3H), 4.81 (s, 3H), 2.56 (s, 3H), 1.93 - 1.81 (m, 2H), 0.89 (t, J = 7.3 Hz, 3H).

[0569] 2.16: (S)-1-(4-aminobenzyl)-3-((4-ethyl-8-fluoro-4-hydroxy-9-methoxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)urea (compound 135) [ka] The title compound was prepared according to General Procedure 4, Step 2, using compound 2.14 (15 mg) as the PNP-carbamate and 4-(aminomethyl)aniline as the primary amine. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 20 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 2.1 mg, 12% yield).

[0570] LC / MS:C 30 H 28 Calculated m / z for FN5O6 = 573.2, found [M+H] + =574.2.

[0571] 1H NMR (300 MHz, MeOD) δ 7.79 (d, J = 11.9 Hz, 1H), 7.74 (d, J = 9.0 Hz, 1H), 7.59 (s, 1H), 7.43 (d, J = 8.2 Hz, 2H), 7.25 (d, J = 8.2 Hz, 2H), 5.61 (d, J = 16.3 Hz, 1H), 5.52 - 5.35 (m, 3H), 4.98 (s, 2H), 4.39 (s, 2H), 4.01 (s, 3H), 2.03 - 1.93 (m, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0572] 2.17: (S)-1-((4-ethyl-8-fluoro-4-hydroxy-9-methoxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-3-(2-hydroxyethyl)urea (compound 137) [ka] The title compound was prepared according to General Procedure 4, Step 2, using compound 2.14 (15 mg) as the PNP-carbamate and hydroxyethylamine as the primary amine. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 20 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (1.5 mg, 12% yield).

[0573] LC / MS:C 25 H 25 Calculated m / z for FN4O7 = 512.2, observed [M+H] + =513.2.

[0574] 1H NMR (300 MHz, MeOD) δ 7.93 (d, J = 12.1 Hz, 1H), 7.88 (d, J = 9.2 Hz, 1H), 7.56 (s, 1H), 5.62 (d, J = 16.2 Hz, 1H), 5.52 (s, 2H), 5.45 (d, J = 16.3 Hz, 1H), 4.98 (s, 2H), 4.17 (s, 3H), 3.59 (t, J = 5.6 Hz, 2H), 3.28 (t, J = 5.6 Hz, 2H), 2.10 - 1.91 (m, 2H), 1.05 (t, J = 7.3 Hz, 3H).

[0575] Example 3: Preparation of camptothecin analogs with an amino at the C10 position 3.1: 5-Bromo-4-fluoro-2-nitrobenzaldehyde (compound 3.1) [ka] To a stirred solution of HNO (121.2 mL, 67% purity, 2.0 equiv.) in HSO (500 mL) at 0 °C was added 3-bromo-4-fluorobenzaldehyde (180 g, 1.0 equiv.). After the addition was complete, the ice bath was removed and the reaction was stirred at 25 °C for 5 h. The mixture was poured onto ice (5 L), filtered, and then dried under reduced pressure. The title compound was obtained as a yellow solid (219 g).

[0576] 1 H NMR (400 MHz, CDCl3) δ 10.39 (s, 1H), 8.23 ​​(d, J = 6.8 Hz, 1H), 7.91 (d, J = 7.6 Hz, 1H).

[0577] 3.2: tert-Butyl (2-fluoro-5-formyl-4-nitrophenyl)carbamate (compound 3.2) [ka] A mixture of compound 3.1 (219 g, 1.0 equiv.), tert-butyl carbamate (124 g, 1.20 equiv.), CsCO (575 g, 2.0 equiv.), Pd(dba) (40 g, 0.05 equiv.), and XPhos (84 g, 0.2 equiv.) in toluene (2000 mL) was degassed and purged with N for three cycles. The mixture was then stirred at 90 °C under a N atmosphere for 15 h. The reaction mixture was diluted with HO (800 mL) and extracted with EtOAc (300 mL × 2). The combined organic layers were washed with brine (200 mL × 2), then dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (SiO2, petroleum ether:ethyl acetate = 100:1 to 20:1) to give the title compound as a yellow solid (140 g, 56% yield).

[0578] 1 H NMR (400 MHz, DMSO-d6) δ 10.24 (s, 1H), 9.94 (s, 1H), 8.42 (d, J=7.6 Hz, 1H), 8.16 (d, J=10.8 Hz, 1H), 1.50 (s, 9H).

[0579] 3.3: tert-Butyl (4-amino-2-fluoro-5-formylphenyl)carbamate (compound 3.3) [ka] To a solution of compound 3.2 (100 g, 1.0 equiv.) in HO (300 mL) and EtOH (1200 mL) was added NH4Cl (30.5 g, 1.62 equiv.). Iron (78.6 g, 4.0 equiv.) was added portionwise at 80 °C. The mixture was stirred at 80 °C for 6 h. The mixture was filtered, water was added to the filtrate, and the resulting mixture was extracted with ethyl acetate. The organic layer was washed with brine, dried over sodium sulfate, and concentrated under reduced pressure. The residue was purified by column chromatography (SiO2, petroleum ether:ethyl acetate = 1:0 to 0:1) and TLC (petroleum ether) to give the title compound as a yellow solid (19.0 g, 21% yield).

[0580] LC / MS:C 12 H 15 Calculated m / z for FN2O3 = 254.1, observed [M+H] + =255.0.

[0581] 1 H NMR (400 MHz, DMSO-d6) δ 9.73 (s, 1 H), 8.57 (s, 1 H), 7.58 (d, J = 4.8 Hz, 1 H), 7.21 (s, 2 H), 6.53 (d, J = 12.8 Hz, 1 H), 1.43 (s, 9 H).

[0582] 3.4: tert-Butyl (S)-(4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)carbamate (compound 3.4) [ka] A mixture of compound 3.3 (4.20 g, 1.2 equivalents), (S)-4-ethyl-4-hydroxy-7,8-dihydro-1H-pyrano[3,4-f]indolizine-3,6,10(4H)-trione (3.5 g, 1 equivalent), and TsOH (monohydrate, 253 mg, 0.1 equivalent) in toluene (350 mL) was stirred at 110 °C for 2 hours. The reaction solution was cooled to 25 °C and filtered. The solid was washed with methyl t-butyl ether (30 mL) and then dried under reduced pressure. The title compound was obtained as a yellow solid (4.5 g, 62% yield).

[0583] LC / MS:C 25 H 24 Calculated m / z for FN3O6 = 481.2, observed [M+H] + =482.1.

[0584] 1H NMR (400 MHz, DMSO-d6) δ 9.49 (s, 1H), 8.65 (s, 1H), 8.43 (d, J =8.4 Hz, 1H), 7.95 (d, J = 12.0 Hz, 1H), 7.30 (s, 1H), 6.51 (s, 1H), 5.42 (s, 2H), 5.25 (s, 2H), 1.80 - 1.92 (m, 2H), 1.52 (s, 9H), 0.88 (t, J = 7.2 Hz, 3H).

[0585] 3.5: tert-Butyl (S)-(4-ethyl-8-fluoro-4-hydroxy-11-(hydroxymethyl)-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)carbamate (compound 3.5) [ka] To a mixture of compound 3.4 (4.00 g) in MeOH (360 mL) was added a solution of FeSO (heptahydrate, 1.2 g) and HSO (280 μL) in HO (4 mL). The reaction mixture was heated to 65 °C while HO (24 mL, 30% purity) was added dropwise over 30 min and stirred for 0.5 h. The reaction solution was cooled to 25 °C and filtered to give the title compound as a yellow solid (1.53 g, 33.2% yield). HO (400 mL) was added to the filtrate and quenched with saturated aqueous NaSO. The pH was adjusted to 7-8 with saturated aqueous NaCO, and the solution was concentrated and filtered. The solid was triturated with MeOH (30 mL) at 55 °C for 1 h and then filtered to give a second batch of the title compound as a brown solid (1.09 g, 26% yield).

[0586] LC / MS:C 26 H 26 Calculated m / z for FN3O7 = 511.2, observed [M+H] + =512.2.

[0587] 1H NMR (300 MHz, d6-DMSO) δ 9.47 (s, 1H), 8.47 (d, J =7.6 Hz, 1H), 7.94 (d, J =12.0 Hz, 1H), 7.29 (d, J =1.6 Hz, 1H), 6.49 (s, 1H), 5.86 - 5.76 (m, 1H), 5.42 (s, 2H), 5.38 (s, 2H), 5.16 (d, J =4.4 Hz, 2H), 1.90 - 1.83 (m, 2H), 1.52 (s, 9H), 0.88 (t, J = 6.4 Hz, 3H).

[0588] 3.6: tert-Butyl (S)-(4-ethyl-8-fluoro-11-formyl-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)carbamate (compound 3.6) [ka] To a 50 mL round-bottom flask containing compound 3.5 (150 mg, 0.293 mmol) was added DCM (2.9 mL), followed by Dess-Martin periodinane (0.56 g, 1.32 mmol) and water (15.8 μL, 0.88 mmol). The solution was stirred at room temperature for 18 h, then diluted with DCM and washed with saturated aqueous NaHCO3 and brine. The layers were separated, and the combined organic layer was evaporated onto Celite. Flash purification was performed as described in General Procedure 9 using a 10 g silica column eluting with 0 to 10% DCM / MeOH to give the title product as an orange powder (42.5 mg, 28%).

[0589] LC / MS:C 26 H 24 Calculated m / z for FN3O7 = 509.2, found [M+H] + =510.4.

[0590] 1H NMR (300 MHz,acetone-d6) δ 11.10 (s, 1H), 9.68 (d, J =8.6 Hz, 1H), 8.81 (s, 1H), 8.04 (d, J =11.9 Hz, 1H), 7.63 (s, 1H), 5.73 (s, 2H), 5.69 (d, J =16.2 Hz, 1H), 5.42 (d, J =16.2 Hz, 1H), 2.02-1.95 (m, 2H), 8.47 (d, J =7.6 Hz, 1H), 7.94 (d, J =12.0 Hz, 1H), 7.29 (d, J =1.6 Hz, 1H), 6.49 (s, 1H), 5.86 - 5.76 (m, 1H), 5.42 (s, 2H), 5.38 (s, 2H), 5.16 (d, J =4.4 Hz, 2H), 1.90 - 1.83 (m, 2H), 1.52 (s, 9H), 0.88 (t, J = 6.4 Hz, 3H).

[0591] 3.7: (S)-9-Amino-4-ethyl-8-fluoro-4-hydroxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 140) [ka] The title compound was prepared according to general procedure 6 starting from compound 3.4 (40 mg) to afford the title compound as a red solid (TFA salt, 36 mg, 87% yield).

[0592] LC / MS:C 20 H 16 Calculated m / z for FN3O4 = 381.1, observed [M+H] + =382.2.

[0593] 1H NMR (300 MHz, DMSO) δ 8.28 (s, 1H), 7.72 (d, J = 12.5 Hz, 1H), 7.21 (d, J = 7.3 Hz, 1H), 5.43 (d, J = 16.2 Hz, 1H), 5.34 (d, J = 16.2 Hz, 1H), 5.17 (s, 2H), 1.92 - 1.74 (m, 2H), 0.88 (t, J = 7.3 Hz, 3H).

[0594] 3.8: (S)-9-Amino-4-ethyl-8-fluoro-4-hydroxy-11-(hydroxymethyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 141) [ka] The title compound was prepared according to general procedure 6 starting from compound 3.5 (5 mg) to afford the title compound as a red solid (TFA salt, 4.1 mg, 78% yield).

[0595] LC / MS:C 21 H 18 Calculated m / z for FN3O5 = 411.2, observed [M+H] + =412.2.

[0596] 1 H NMR (300 MHz, MeOD) δ 7.71 (d, J = 12.2 Hz, 1H), 7.60 (s, 1H), 7.29 (d, J = 9.5 Hz, 1H), 5.61 (d, J = 16.3 Hz, 1H), 5.47 (s, 2H), 5.40 (d, J = 16.3 Hz, 1H), 5.25 (s, 2H), 2.03 - 1.94 (m, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0597] 3.9: tert-Butyl (S)-(11-(chloromethyl)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)carbamate (compound 3.9) [ka] To a stirred solution of compound 3.5 (100 mg) in dichloromethane (5 mL) was added a solution of thionyl chloride (14 μL) in dichloromethane (0.1 mL). After 1 hour, additional thionyl chloride (14 μL) in dichloromethane (0.1 mL) was added. After another hour, the reaction was diluted with dichloromethane (10 mL) and toluene (1 mL) and then concentrated in vacuo to give the title compound as a red solid, which was used in the next reaction without further purification.

[0598] LC / MS:C 26 H 25 Calculated m / z for ClFN3O6 = 529.1, found [M+H] + =530.2.

[0599] 3.10: tert-Butyl (S)-(11-(aminomethyl)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)carbamate (compound 3.10) [ka] To compound 3.9 (100 mg) in ethanol (500 μL) was added hexamethylenetetramine (79 mg), followed by DIPEA (99 μL). The solution was heated at 60° C. for 16 hours and then concentrated to dryness in vacuo. Flash purification was performed as described in General Procedure 9 using a 12 g C18 column eluted with a 10-50% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 29 mg, 24% yield).

[0600] LC / MS:C 26 H 27 Calculated m / z for FN4O6 = 510.2, observed [M+H] + =511.4.

[0601] 1 H NMR (300 MHz, MeOD) δ 8.88 (d, J = 8.2 Hz, 1H), 7.96 (d, J = 11.9 Hz, 1H), 7.62 (s, 1H), 5.60 (d, J = 16.4 Hz, 1H), 5.48 (s, 2H), 5.41 (d, J = 16.4 Hz, 1H), 4.80 (s, 2H), 2.07 - 1.89 (m, 2H), 1.64 (s, 9H), 1.02 (t, J = 7.3 Hz, 3H).

[0602] 3.11: (S)-9-Amino-11-(aminomethyl)-4-ethyl-8-fluoro-4-hydroxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 145) [ka] The title compound was prepared according to general procedure 6 starting from compound 3.10 (2.1 mg) to afford the title compound as a red solid (TFA salt, 1.8 mg, 100% yield).

[0603] LC / MS:C 21 H 19 Calculated m / z for FN4O4 = 410.1, found [M+H] + =411.2.

[0604] 1H NMR (300 MHz, MeOD) δ 7.82 (d, J = 12.1 Hz, 1H), 7.60 (s, 1H), 7.37 (d, J = 9.1 Hz, 1H), 5.61 (d, J = 16.3 Hz, 1H), 5.42 (s, 2H), 5.41 (d, J = 16.3 Hz, 1H), 4.69 (s, 2H), 2.08 - 1.94 (m, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0605] Example 3.12: (S)-9-Amino-4-ethyl-8-fluoro-4-hydroxy-11-(morpholinomethyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (Compound 3.12) [ka] The title compound was prepared according to general procedure 1 starting from compound 3.9 (150 mg) and morpholine. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as a red solid (TFA salt, 103 mg, 52% yield).

[0606] LC / MS:C 30 H 33 Calculated m / z for FN4O7 = 580.2, observed [M+H] + =581.4.

[0607] 1H NMR (300 MHz, MeOD) δ 9.06 (d, J = 8.3 Hz, 1H), 7.93 (d, J = 12.0 Hz, 1H), 7.66 (s, 1H), 5.63 (d, J = 16.3 Hz, 1H), 5.51 (s, 2H), 5.43 (d, J = 16.4 Hz, 1H), 4.92 (s, 2H), 3.84 (s, 4H), 3.10 (s, 4H), 1.99 (d, J = 5.5 Hz, 2H), 1.63 (s, 9H), 1.03 (t, J = 7.4 Hz, 3H).

[0608] 3.13: (S)-9-Amino-4-ethyl-8-fluoro-4-hydroxy-11-(morpholinomethyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 142) [ka] The title compound was prepared according to general procedure 6 starting from compound 3.12 (45 mg) to afford the title compound as a red solid (TFA salt, 37 mg, 99% yield).

[0609] LC / MS:C 25 H 25 Calculated m / z for FN4O5 = 480.2, observed [M+H] + =481.4.

[0610] 1 H NMR (300 MHz, MeOD) δ 7.73 (d, J = 12.0 Hz, 1H), 7.54 (s, 1H), 7.48 (d, J = 9.2 Hz, 1H), 5.60 (d, J = 16.3 Hz, 1H), 5.47 - 5.34 (m, 3H), 4.65 (s, 2H), 3.91 - 3.85 (m, 4H), 3.30 - 3.24 (m, 4H), 2.08 - 1.91 (m, 2H), 1.02 (t, J = 7.3 Hz, 3H).

[0611] 3.14: (S)-9-Amino-4-ethyl-8-fluoro-4-hydroxy-11-(piperidin-1-ylmethyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 148) [ka] To a 5 mL flask containing compound 3.6 (37 mg, 0.067 mmol) was added dichloromethane (1.45 mL), followed by acetic acid (18.69 μL, 0.327 mmol), piperidine (21.52 μL, 0.218 mmol), and sodium triacetoxyborohydride (23.0 mg, 0.109 mmol). The solution was then stirred at room temperature for 2 h, quenched by the addition of water + 0.1% TFA and DMF (1:1, 1.0 mL), and partially evaporated. Purification was carried out as described in General Procedure 9 using a 12 g C18 flash column eluted with a 5 to 40% CH3CN / HO + 0.1% TFA gradient to give the Boc-protected intermediate as a yellow powder. This intermediate was then deprotected according to general procedure 6 to give the title compound as a yellow solid (TFA salt, 32.5 mg, 98% yield).

[0612] LC / MS:C 26 H 27 Calculated m / z for FN4O4 = 478.2, observed [M+H] + =479.4.

[0613] 1 H NMR (300 MHz, MeOD) δ 7.78 (d, J = 12.1 Hz, 1H), 7.56 (s, 1H), 7.41 (d, J = 9.1 Hz, 1H), 5.60 (d, J = 16.4 Hz, 1H), 5.47 - 5.35 (m, 3H), 4.86 (s, 2H), 3.80 - 3.68 (m, 2H), 3.28 - 3.19 (m, 2H), 2.02 - 1.68 (m, 8H), 1.01 (t, J = 7.4 Hz, 3H).

[0614] 3.15: (S)-9-Amino-4-ethyl-8-fluoro-4-hydroxy-11-((4-methylpiperazin-1-yl)methyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 149) [ka] To a 2 mL vial containing compound 3.6 (15 mg, 0.029 mmol) was added dichloromethane (0.59 mL), acetic acid (7.58 μL, 0.132 mmol), and N-methylpiperazine (4.90 μL, 0.044 mmol). The solution was stirred at room temperature for 4 h, followed by the addition of sodium triacetoxyborohydride (7.8 mg, 0.037 mmol) and stirring for an additional 45 min. The excess hydride was quenched by the addition of 0.1% aqueous TFA (0.5 mL). Purification was carried out as described in General Procedure 9 using a 12 g C18 flash column eluting with a 5 to 40% CH3CN / HO + 0.1% TFA gradient to give the Boc-protected intermediate as a yellow powder. This intermediate was deprotected according to general procedure 6 to give the title product as a yellow solid (TFA salt, 1.5 mg, 7.1% yield).

[0615] LC / MS:C 26 H 28 Calculated m / z for FN5O4 = 493.2, observed [M+H] + =494.4.

[0616] 1H NMR (300 MHz, MeOD) δ 7.68 (d, J = 12.2 Hz, 1H), 7.56 (s, 1H), 7.53 (d, J = 9.5 Hz, 1H), 5.60 (d, J = 16.3 Hz, 1H), 5.45-5.30 (m, 3H), 4.15 (s, 2H), 3.55 - 3.44 (m, 2H), 3.18 - 3.07 (m, 2H), 2.93 (s, 3H), 2.70 - 2.51 (m, 2H), 2.03 - 1.89 (m, 2H), 1.02 (t, J = 7.4 Hz, 3H).

[0617] 3.16: (S)-9-Amino-4-ethyl-8-fluoro-4-hydroxy-11-((4-(phenylsulfonyl)piperazin-1-yl)methyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 153) [ka] The Boc-protected precursor of the title compound was prepared according to General Procedure 1, starting from compound 3.9 (10 mg) and 1-(phenylsulfonyl)piperazine. Preparative HPLC was performed as described in General Procedure 9, eluting with a 35 to 44% CHCN / HO + 0.1% TFA gradient, to give the Boc-protected intermediate as a yellow powder. This intermediate was then deprotected according to General Procedure 6 to give the title compound (TFA salt, 2.4 mg, 17% yield over two steps).

[0618] LC / MS:C 31 H 30 Calculated m / z for FN5O6S = 619.2, observed [M+H] + =520.4.

[0619] 1H NMR (300 MHz, MeOD) δ 7.81-7.60 (m, 7H), 7.34 (s, 1H), 5.51 (d, J = 16.4 Hz, 1H), 5.35 (d, J = 16.4 Hz, 1H), 5.22 (s, 2H), 4.10 (s, 2H), 3.15-3.02 (m, 4H), 2.79-2.71 (m, 4H), 2.00-1.93 (m, 2H), 1.00(t,J= 7.4 Hz, 3H).

[0620] 3.17: (S)—N-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)acetamide (compound 147) [ka] The title compound was prepared according to general procedure 2 followed by general procedure 6 starting from compound 3.10 (8 mg) and acetic acid. Preparative HPLC purification of the intermediate Boc-protected compound was performed as described in general procedure 9, eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient. The title compound was obtained as a red solid (4.0 mg, 56% yield).

[0621] LC / MS:C 23 H 21 Calculated m / z for FN4O5 = 452.2, observed [M+H] + =453.2.

[0622] 1 H NMR (300 MHz, MeOD) δ 7.69 (d, J = 12.1 Hz, 1H), 7.56 (s, 1H), 7.38 (d, J = 9.3 Hz, 1H), 5.59 (d, J = 16.3 Hz, 1H), 5.44 - 5.33 (m, 3H), 4.85 (s, 3H), 2.03 (s, 3H), 2.00 - 1.84 (m, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0623] 3.18: (S)—N-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)methanesulfonamide (compound 146) [ka] The title compound was prepared according to general procedure 3 followed by general procedure 6 starting from compound 3.10 (8 mg) and methanesulfonyl chloride. Preparative HPLC purification of the intermediate Boc-protected compound was performed as described in general procedure 9, eluting with a 10 to 60% CHCN / HO+0.1% TFA gradient. The title compound was obtained as a red solid (4.4 mg, 57% yield).

[0624] LC / MS:C 22 H 21 Calculated m / z for FN4O6S = 488.1, observed [M+H] + =489.2.

[0625] 1 H NMR (300 MHz, MeOD) δ 7.74 (d, J = 12.2 Hz, 1H), 7.60 (s, 1H), 7.49 (d, J = 9.3 Hz, 1H), 5.61 (d, J = 16.2 Hz, 1H), 5.45 (s, 2H), 5.40 (d, J = 16.2 Hz, 1H), 4.78 (s, 2H), 3.05 (s, 3H), 2.08 - 1.94 (m, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0626] 3.19: (S)—N-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-2-hydroxyethane-1-sulfonamide (compound 150) [ka] The title compound was prepared according to general procedure 3 followed by general procedure 6 starting from compound 3.10 (6 mg) and 2-hydroxyethanesulfonyl chloride. Preparative HPLC purification of the intermediate Boc-protected compound was performed as described in general procedure 9, eluting with a 10 to 60% CHCN / HO+0.1% TFA gradient. The title compound was obtained as a red solid (1 mg, 16% yield).

[0627] LC / MS:C 23 H 23 Calculated m / z for FN4O7S = 518.5, observed [M+H] + =519.5.

[0628] 1 H NMR (300 MHz, 10% D2O / CD3CN) δ 7.77 - 7.61 (m, 1H), 7.48 - 7.30 (m, 2H), 5.53 (d, J = 16.3 Hz, 1H), 5.31 (d, J = 15.4 Hz, 3H), 4.69 (s, 2H), 3.97 (dd, J = 6.6, 4.9 Hz, 2H), 3.39 (t, J = 5.8 Hz, 2H), 2.93 (s, 1H), 1.99-1.83 (m, 2H), 0.94 (t, J = 7.3 Hz, 3H).

[0629] 3.20: 4-Nitrophenyl (S)-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamate (compound 3.20) [ka] To a solution of compound 3.10 (10 mg, 0.02 mmol) in DMF (400 μL, 0.05 M) was added 4-nitrophenyl carbonate (12 mg, 0.04 mmol) and diisopropylethylamine (6.8 μL, 0.04 mmol). The solution was stirred at room temperature for about 30 minutes and then used directly in the next reaction.

[0630] 3.21: Methyl (S)-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamate (compound 143) [ka] The title compound was prepared by adding MeOH (100 uL) to a solution of 200 uL of compound 3.20. The solution was stirred at room temperature for 30 minutes. Preparative HPLC purification of the intermediate Boc-protected compound was performed as described in General Procedure 9, eluting with a 10-60% CHCN / HO + 0.1% TFA gradient. The title compound was obtained as a red solid (2.1 mg, 47% yield) following General Procedure 6.

[0631] LC / MS:C 23 H 21 Calculated m / z for FN4O6 = 468.4, observed [M+H] + =468.3.

[0632] 1 H NMR (300 MHz, 10% D2O / CD3CN) δ 7.72 (d, J = 12.2 Hz, 1H), 7.41 (d, J = 18.1 Hz, 1H), 6.96 (s, 1H), 5.52 (d, J = 3.6 Hz, 1H), 5.39 - 5.23 (m, 3H), 4.82 (s, 1H), 4.73 (s, 1H), 3.63 (d, J = 1.2 Hz, 3H), 1.56 (s, 3H), 1.27 (s, 2H), 0.94 (t, J = 7.4 Hz, 3H).

[0633] 3.22: (S)-1-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-3-methylurea (compound 144) [ka] The title compound was prepared by adding methylamine hydrochloride (10 mg) to a 200 μL solution of compound 3.20, followed by iPrNEt (5 μL). The solution was stirred at room temperature for 30 minutes. Preparative HPLC purification of the intermediate Boc-protected compound was performed as described in General Procedure 9, eluting with a 10-60% CHCN / HO + 0.1% TFA gradient. The title compound was obtained as a red solid (2.9 mg, 64.5% yield) following General Procedure 6.

[0634] LC / MS:C 23 H 21 Calculated m / z for FN5O5 = 467.5, observed [M+H] + =468.5.

[0635] 1 H NMR (300 MHz, 10% D2O / CD3CN) δ 8.13 (d, J = 9.2 Hz, 1H), 7.92 (s, 1H), 7.73 (d, J = 12.3 Hz, 1H), 7.52 - 7.35 (m, 2H), 6.94 (d, J = 9.2 Hz, 2H), 5.55 (d, J = 16.5 Hz, 2H), 5.44 - 5.27 (m, 4H), 4.85 (s, 2H), 4.78 (s, 1H), 1.56 (d, J = 2.5 Hz, 3H), 1.27 (s, 2H), 0.93 (q, J = 11.7, 9.5 Hz, 3H).

[0636] 3.23: (S)-1-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-3-(2-hydroxyethyl)urea (compound 151) [ka] The title compound was prepared by adding ethanolamine (100 uL) to a solution of 200 uL of compound 3.20. The solution was stirred at room temperature for 30 minutes. Preparative HPLC purification of the intermediate Boc-protected compound was performed as described in General Procedure 9, eluting with a 10-60% CHCN / HO + 0.1% TFA gradient. The title compound was obtained as a red solid (0.5 mg, 8.5% yield) following General Procedure 6.

[0637] LC / MS:C 24 H 24 Calculated m / z for FN5O6 = 497.5, observed [M+H] + =498.5.

[0638] 1 H NMR (300 MHz, 10% D2O / CD3CN) δ 7.77 - 7.61 (m, 1H), 7.48 - 7.30 (m, 2H), 5.53 (d, J = 16.3 Hz, 1H), 5.31 (d, J = 15.4 Hz, 1H), 5.19 (s, 2H), 4.69 (s, 2H), 3.97 (dd, J = 6.6, 4.9 Hz, 2H), 3.39 (t, J = 5.8 Hz, 2H), 2.93 (s, 1H), 2.01-1.83 (m, 2H), 0.94 (t, J = 7.3 Hz, 3H).

[0639] 3.24: (S)-9-Amino-11-(azidomethyl)-4-ethyl-8-fluoro-4-hydroxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 152) [ka] To a stirred solution of compound 3.5 (100 mg) in 2 mL of dichloromethane was added thionyl chloride (35 μL, 2.5 equiv.). The solution was stirred at room temperature for 20 minutes, after which additional thionyl chloride (35 μL, 2.5 equiv.) was added. After 20 minutes, toluene (1 mL) was added, and the reaction mixture was concentrated in vacuo. The crude solid was suspended in DMSO (1 mL), and sodium azide (19 mg, 1.5 equiv.) was added. The solution was stirred at room temperature for 16 hours. Purification was carried out as described in General Procedure 9, eluting with a 5-50% CHCN / HO + 0.1% TFA gradient, to afford the title compound as an off-white solid (20 mg, 23% yield).

[0640] LC / MS:C 21 H 17 Calculated m / z for FN6O4 = 436.1, observed [M+H] + =437.2.

[0641] 1 H NMR (300 MHz, MeOD) δ 7.75 (d, J = 12.2 Hz, 1H), 7.60 (s, 1H), 7.38 (d, J = 9.3 Hz, 1H), 5.61 (d, J = 16.3 Hz, 1H), 5.46 - 5.35 (m, 3H), 5.07 (s, 2H), 2.03 - 1.97 (m, 2H), 1.03 (t, J = 7.3 Hz, 3H).

[0642] 3.25: (S)-N-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)acetamide (compound 164) [ka] The title compound was prepared according to general procedure 2 starting from compound 145 (10 mg) and glycolic acid. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 10 to 45% CHCN / HO + 0.1% TFA gradient. The title compound was obtained as a yellow solid (6.9 mg, 60% yield).

[0643] LC / MS:C 23 H 21 Calculated m / z for FN4O6 = 468.1, observed [M+H] + =469.2.

[0644] 1 H NMR (300 MHz, MeOD) 7.70 (d, J = 12.2 Hz, 1H), 7.60 (s, 1H), 7.42 (d, J = 9.4 Hz, 1H), 5.62 (d, J = 16.3 Hz, 1H), 5.43 (s, 2H), 5.36 (d, J = 16.2 Hz, 1H), 4.95 (d, J = 5.9 Hz, 2H), 4.08 (s, 2H), 2.04 - 1.90 (m, 1H), 1.03 (t, J = 7.4 Hz, 3H).

[0645] 3.26: (S)-1-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-3-methylthiourea (compound 161) [ka] To a solution of compound 145 (9 mg, 1.0 equiv.) in DMF (1 mL) was added thiocarbonyldiimidazole (6 mg, 1.5 equiv.), followed by DIPEA (8 μL, 2.0 equiv.). The resulting solution was stirred at 25° C. for 2 h, after which complete conversion to the isothiocyanate intermediate was confirmed. Methylammonium chloride (3 mg, 2.0 equiv.) was then added, and the reaction mixture was heated at 60° C. for 30 min. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 10 to 45% CHCN / HO + 0.1% TFA gradient. The title compound was obtained as a yellow solid (2.3 mg, 22% yield).

[0646] LC / MS:C 23 H 22 Calculated m / z for FN5O4S = 483.1, observed [M+H] + =484.2.

[0647] 1 H NMR (300 MHz, MeOD) δ 7.70 (d, J = 12.0 Hz, 1H), 7.60 (s, 1H), 7.38 (d, J = 9.3 Hz, 1H), 5.62 (d, J = 16.2 Hz, 1H), 5.36 (s, 2H), 5.31 (d, J = 16.2 Hz, 1H), 5.30 (s, 2H), 3.04 (s, 3H), 1.99 - 1.90 (m, 2H), 1.02 (t, J = 7.4 Hz, 3H).

[0648] 3.27: S-(2-Hydroxyethyl)-(S)-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamothioate (compound 160) [ka] The title compound was prepared according to general procedure 5 starting from compound 145 (10 mg) and 2-mercaptoethanol. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 10 to 45% CHCN / HO + 0.1% TFA gradient. The title compound was obtained as a yellow solid (4.2 mg, 43% yield).

[0649] LC / MS:C 24 H 23 Calculated m / z for FN4O6S = 514.1, observed [M+H] + =515.2.

[0650] 1 H NMR (300 MHz, MeOD) δ 7.71 (d, J = 12.1 Hz, 1H), 7.60 (s, 1H), 7.36 (d, J = 9.4 Hz, 1H), 5.62 (d, J = 16.3 Hz, 1H), 5.42 (s, 2H), 5.35 (d, J = 16.2 Hz, 1H), 4.88 (d, J = 4.6 Hz, 2H), 3.68 (t, J = 6.4 Hz, 2H), 3.03 (t, J = 6.5 Hz, 2H), 2.04 - 1.92 (m, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0651] 3.28: (S)-9-Amino-4,11-diethyl-8-fluoro-4-hydroxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 154) [ka] To a 5 mL flask containing compound 140 (50 mg) were added water (0.72 mL), FeSO (heptahydrate, 11.0 mg), and propionaldehyde (74 μL). The resulting suspension was cooled to −15 °C using an ice-salt water bath, and then sulfuric acid (0.40 mL) was added dropwise. Hydrogen peroxide (95 μL) was then added dropwise. The mixture was stirred at −15 °C for 10 min, then warmed to room temperature, and stirred for 2 h. The reaction mixture was diluted with water (30 mL), and the resulting suspension was extracted with DCM (3 × 30 mL). The organic phase was then evaporated to dryness. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 25 to 70% CHCN / HO + 0.1% TFA gradient, to give the title compound as a dark orange solid (2.4 mg, 4.4% yield).

[0652] LC / MS:C 22 H 20 Calculated m / z for FN3O4 = 410.1, found [M+H] + =410.2.

[0653] 1 H NMR (300 MHz, MeOD) δ 7.63 (d, J = 12.3 Hz, 1H), 7.55 (s, 1H), 7.36 (d, J = 9.4 Hz, 1H), 5.57 (d, J = 16.4 Hz, 1H), 5.37 (d, J = 16.4 Hz, 1H), 5.21 (s, 2H), 3.13 (q, J = 7.7 Hz, 2H), 2.02 - 1.90 (m, 2H), 1.38 (t, J = 7.7 Hz, 3H), 1.01 (t, J = 7.3 Hz, 3H).

[0654] 3.29: tert-Butyl-(S)-(11-((carbamoyloxy)methyl)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)carbamate (compound 3.29) [ka] Compound 3.5 (15 mg) was added to a 5 mL Erlenmeyer flask containing a solution of chlorosulfonyl isocyanate (7.7 μL) in dimethylformamide (0.29 mL) at −20° C. The resulting suspension was stirred at −20° C. for 5 minutes. Water (59 μL) was added, and the reaction mixture was warmed to room temperature and stirred for 2 hours, then heated at 70° C. for 1 hour. The reaction mixture was cooled to room temperature and partially evaporated. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 40-55% CH3CN / HO + 0.1% TFA gradient, to afford the title compound as a dark orange solid (5.1 mg, 31% yield).

[0655] LC / MS:C 27 H 27 Calculated m / z for FN4O8 = 555.2, observed [M+H] + =555.2.

[0656] 1 H NMR (300 MHz, DMSO-d6) δ 9.53 (s, 1H), 8.56 (d, J = 8.5 Hz, 1H), 8.00 (d, J = 12.0 Hz, 1H), 7.31 (s, 1H), 7.11-6.62 (m, 2H), 6.52 (s, 1H), 5.58 (s, 2H), 5.49-5.27 (m, 4H), 1.94-1.77 (m, 2H), 1.52 (s, 9H), 1.38 (t, J = 7.7 Hz, 3H), 0.87 (t, J = 7.2 Hz, 3H).

[0657] 3.30: (S)-(9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methylcarbamate (compound 169) [ka] The title compound was prepared according to general procedure 6 starting from compound 3.29 (5.1 mg) to afford the title compound as a yellow powder (TFA salt, 3.8 mg, 73% yield).

[0658] LC / MS:C 22 H 19 Calculated m / z for FN4O6 = 455.1, observed [M+H] + =455.2.

[0659] 1 H NMR (300 MHz, DMSO-d6) δ 7.79 (d, J = 12.4 Hz, 1H), 7.29 (d, J = 9.7 Hz, 1H), 7.21 (s, 1H), 7.0-6.50 (m, 2H), 5.45 (s, 2H), 5.40 (s, 2H), 5.33 (s, 2H), 1.95-1.77 (m, 2H), 0.87 (t, J = 7.3 Hz, 3H).

[0660] 3.31: (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-11-(methoxymethyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 155) [ka] To a 50 mL flask containing compound 3.5 (30 mg) were added MeOH / dioxane (1:1) (9.8 mL) and sulfuric acid (0.73 mL). The reaction mixture was then stirred at reflux for 24 hours. The reaction mixture was concentrated, poured into water (30 mL), and extracted with DCM (3 x 50 mL). The organic phases were combined and dried over MgSO. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 25-40% CHCN / HO + 0.1% TFA gradient, to afford the title compound (5.1 mg, 16% yield) as a dark orange solid.

[0661] LC / MS:C 22 H 20Calculated m / z for FN3O5 = 426.1, found [M+H]+ = 426.2.

[0662] 1 H NMR (300 MHz, DMSO-d6) δ 7.75 (d, J = 12.3 Hz, 1H), 7.24 (d, J = 9.9 Hz, 1H), 7.20 (s, 1H), 6.47 (s, 1H), 6.30-5.92 (brs, 2H), 5.40 (s, 2H), 5.24 (s, 2H), 4.93 (s, 2H), 3.43 (s, 3H), 1.95-1.75 (m, 2H), 0.87 (t, J = 7.3 Hz, 3H).

[0663] 3.32: (4S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-11-(((1R,5S)-6-hydroxy-3-azabicyclo[3.1.1]heptan-3-yl)methyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 158) [ka] To a 5 mL Erlenmeyer flask containing compound 3.6 (15 mg) was added dichloromethane (0.6 mL), followed by 3-azabicyclo[3.1.1]heptan-6-ol (10 mg) and acetic acid (7.6 μL). The reaction was stirred at room temperature, and sodium triacetoxyborohydride (9.4 mg) was added. After 1 h at room temperature, the reaction was quenched by the addition of water + 0.1% TFA and diluted with DMF. The reaction mixture was then partially evaporated. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 20 to 50% CHCN / HO + 0.1% TFA gradient, to afford the Boc-protected title compound as a yellow powder. Deprotection was carried out according to general procedure 6, and the resulting residue was purified by preparative HPLC purification as described in general procedure 9, eluting with a 20 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as a yellow powder (TFA salt, 7.1 mg, 39% yield).

[0664] LC / MS:C 27 H 27 Calculated m / z for FN4O5 = 507.2, [M+H] + =507.4.

[0665] 1 H NMR (300 MHz, DMSO-d6) δ 7.85 (d, J = 12.1 Hz, 1H), 7.46 (d, J = 9.4 Hz, 1H), 7.23 (s, 1H), 6.64-5.85 (m, 3H), 5.60-5.25 (m, 4H), 4.85 (s, 1H), 4.10-3.95 (m, 1H), 3.68 (s, 2H), 2.45-2.33 (m, 2H), 1.96-1.72 (m, 2H), 0.87 (t, J = 7.3 Hz, 3H).

[0666] 3.33: (S)-9-Amino-4-ethyl-8-fluoro-11-((3-fluoro-3-(hydroxymethyl)azetidin-1-yl)methyl)-4-hydroxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 159) [ka] To a 5 mL Erlenmeyer flask containing compound 3.6 (15 mg) was added dichloromethane (0.6 mL), followed by (3-fluoroazetidin-3-yl)methanol (9.3 mg) and acetic acid (7.6 μL). The reaction was stirred at room temperature, and sodium triacetoxyborohydride (9.4 mg) was added. After 1 h at room temperature, the reaction was quenched by the addition of water + 0.1% TFA, diluted with DMF, and partially evaporated. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 20 to 50% CHCN / HO + 0.1% TFA gradient, to give the Boc-protected title compound as a yellow powder. Deprotection was then carried out according to General Procedure 6. The resulting residue was purified by preparative HPLC purification as described in General Procedure 9, eluting with a 20 to 50% CHCN / H0+0.1% TFA gradient to afford the title compound as a yellow powder (TFA salt, 1.8 mg, 10% yield).

[0667] LC / MS:C 25 H 24 Calculated m / z for F2N4O5 = 499.2, found [M+H] + =499.4.

[0668] 1 H NMR (300 MHz, DMSO-d6) δ 7.82 (d, J = 12.4 Hz, 1H), 7.45 (d, J = 9.5 Hz, 1H), 7.21 (s, 1H), 5.45-5.33 (m, 4H), 3.75-3.61 (m, 2H), 1.93-1.78 (m, 2H), 0.87 (t, J = 7.3 Hz, 3H).

[0669] 3.34: tert-Butyl-(S)-(4-ethyl-8-fluoro-4-hydroxy-11-((methylamino)methyl)-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)carbamate (compound 3.34) [ka] To a stirred solution of compound 3.9 (210 mg) in DMF (5 mL) was added sodium iodide (5.9 mg), followed by methylammonium chloride (107 mg). The reaction mixture was then stirred at room temperature overnight. Reverse-phase purification was performed as described in General Procedure 9 using a 30 g C18 column eluted with a 10 to 65% CH3CN / HO + 0.1% TFA gradient to afford the title compound (15.0 mg, 7.2% yield) as a yellow solid.

[0670] LC / MS:C 27 H 29 Calculated m / z for FN4O6 = 524.2, observed [M+H] + =525.4.

[0671] 3.35: (S)-N-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-2-hydroxy-N-methylacetamide (compound 165) [ka] The Boc-protected form of the title compound was prepared according to general procedure 2, starting from compound 3.34 (6.4 mg) and glycolic acid. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 20 to 50% CHCN / HO + 0.1% TFA gradient. Deprotection was then carried out according to general procedure 6 to afford the title compound as a yellow powder (TFA salt, 2.0 mg, 28% yield).

[0672] LC / MS:C 24 H 23 Calculated m / z for FN4O6 = 482.2, observed [M+H] + =483.2.

[0673] 1H NMR (300 MHz, DMSO-d6) δ 7.79 (d, J = 12.3 Hz, 1H), 7.27 (d, J = 9.5 Hz, 1H), 7.22 (s, 1H), 6.48 (s, 1H), 6.28-6.02 (m, 2H), 5.40 (s, 2H), 5.21 (s, 2H), 5.06-4.93 (m, 2H), 4.18 (s, 2H), 2.80 (s, 3H), 1.92-1.78 (m, 2H), 0.87 (t, J = 7.3 Hz, 3H).

[0674] 3.36: (S)-N-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-N-methylmethanesulfonamide (compound 166) [ka] The Boc-protected form of the title compound was prepared according to general procedure 3, starting from compound 3.34 (8.0 mg) and methanesulfonyl chloride. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 10 to 50% CHCN / HO + 0.1% TFA gradient. Deprotection was then carried out according to general procedure 6 to afford the title compound as a yellow powder (TFA salt, 2.6 mg, 34% yield).

[0675] LC / MS:C 23 H 23 Calculated m / z for FN4O6S = 502.1, observed [M+H] + =503.2.

[0676] 1H NMR (300 MHz, DMSO-d6) δ 7.81 (d, J = 12.3 Hz, 1H), 7.41 (d, J = 9.4 Hz, 1H), 7.23 (s, 1H), 6.63-5.84 (m, 2H), 5.42 (s, 2H), 5.29 (s, 2H), 4.81-4.64 (m, 2H), 3.14 (s, 3H), 2.67 (s, 3H), 1.96-1.76 (m, 2H), 0.88 (t, J = 7.3 Hz, 3H).

[0677] 3.37: (S)-9-Amino-4-ethyl-8-fluoro-4-hydroxy-11-(2-methoxyethyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 170) [ka] To a 10 mL round-bottom flask containing compound 3.4 (62.0 mg) were added water (0.89 mL), FeSO (heptahydrate, 18.0 mg), and 3-methoxypropanal (113.0 mg). To the resulting suspension was added sulfuric acid (0.495 mL) dropwise while stirring in an ice-salt bath at −15 °C. Hydrogen peroxide (0.118 mL) was then added dropwise. The mixture was stirred at −15 °C for 10 min, then warmed to room temperature, and stirred for 1 h. The reaction mixture was then diluted with water (30 mL), and the resulting suspension was extracted with DCM (3 × 30 mL). The organic phase was evaporated to dryness. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 25 to 45% CHCN / HO + 0.1% TFA gradient, to afford the title compound as a dark orange solid (TFA salt, 3.1 mg, 4.4% yield).

[0678] LC / MS:C 23 H 22 Calculated m / z for FN3O5 = 440.2, observed [M+H] + =440.2.

[0679] 1H NMR (300 MHz, DMSO-d6) δ 7.75 (d, J = 12.4 Hz, 1H), 7.33 (d, J = 9.4 Hz, 1H), 7.20 (s, 1H), 6.60-6.42 (m, 2H), 5.40 (s, 2H), 5.25 (s, 2H), 3.69 (t, J = 6.5 Hz, 2H), 3.24 (s, 3H), 3.23 (t, J = 6.5 Hz, 2H), 1.96-1.76 (m, 2H), 0.88 (t, J = 7.3 Hz, 3H).

[0680] 3.38: (S)-N-(4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)acetamide (Compound 171) [ka] To a 25 mL round-bottom flask containing acetic acid (0.071 mL) in dimethylformamide (0.69 mL) was added N-methylmorpholine (0.343 mL), HOAt (0.142 g), and HATU (0.435 g). After stirring at room temperature for 5 minutes, the solution was added to a 10 mL conical flask containing compound 140 (0.127 g). Immediately after stirring at room temperature for 24 hours, the solution was purified by preparative HPLC as described in General Procedure 9, eluting with a 25-45% CHCN / HO + 0.1% TFA gradient, to afford the title compound as a bright yellow powder (43.0 mg, 38% yield).

[0681] LC / MS:C 22 H 18 Calculated m / z for FN3O5 = 424.1, observed [M+H] + =424.2.

[0682] 1H NMR (300 MHz, DMSO-d6) δ 10.13 (s, 1H), 8.73 (d, J = 8.5 Hz, 1H), 8.61 (s, 1H), 7.96 (d, J = 912.1 Hz, 1H), 7.29 (s, 1H), 6.60-6.42 (m, 2H), 5.41 (s, 2H), 5.21 (s, 2H), 2.20 (s, 3H), 1.96-1.76 (m, 2H), 0.88 (t, J = 7.3 Hz, 3H).

[0683] 3.39: tert-Butyl (5-formyl-2-methoxy-4-nitrophenyl)carbamate (compound 3.39) [ka] To a solution of compound 3.2 (1.3 g, 1.0 equiv.) in MeOH (12 mL) at 0 °C was added sodium methoxide (0.74 g, 3.0 equiv.). After the addition was complete, the ice bath was removed and the resulting solution was stirred at room temperature for 72 h. The reaction was then quenched with ice water (50 mL) and extracted with DCM (3 x 100 mL). The combined organic layers were washed with brine (50 mL), dried over sodium sulfate, filtered, and concentrated in vacuo to give the title compound as an orange solid (1.2 g, 89% yield).

[0684] LC / MS:C 13 H 16 Calculated m / z for N2O6 = 296.10, observed [M+H] + =297.1.

[0685] 1 H NMR (300 MHz, MeOD) δ 10.29 (s, 1H), 8.61 (s, 1H), 7.73 (s, 1H), 4.08 (s, 3H), 1.57 (s, 9H)

[0686] 3.40: tert-Butyl (4-amino-5-formyl-2-methoxyphenyl)carbamate (compound 3.40) [ka] To a solution of compound 3.39 (500 mg, 1 equiv.) in MeOH (10 mL) and HO (1 mL) was added B(OH) (454 mg, 3 equiv.). The resulting mixture was cooled to 0 °C, and 5 M aqueous NaOH (2.75 mL) was added with stirring over 10 min. The reaction mixture was stirred for an additional 5 min, and then quenched by pouring the solution onto ice (40 mL). The resulting mixture was extracted with DCM (3 × 50 mL), dried over sodium sulfate, filtered, and concentrated in vacuo. Flash purification was performed as described in General Procedure 9 using a 25 g silica column eluting with 10 to 50% hexanes / EtOAc to afford the title compound as an orange solid (386 mg, 86%).

[0687] LC / MS:C 13 H 18 Calculated m / z for N2O4 = 266.1, observed [M+H] + =297.2.

[0688] 3.41: (S)-9-Amino-4-ethyl-8-fluoro-4-hydroxy-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 168) [ka] A mixture of compound 3.40 (385 mg, 1.0 equiv.) and (S)-4-ethyl-4-hydroxy-7,8-dihydro-1H-pyrano[3,4-f]indolizine-3,6,10(4H)-trione (362 mg, 0.95 equiv.), TsOH (monohydrate, 25 mg, 0.1 equiv.), and toluene (30 mL) in a 250 mL round-bottom flask equipped with a Dean-Stark apparatus was stirred at 110° C. for 2 hours. The reaction mixture was then cooled to 25° C. and concentrated under reduced pressure. Purification was carried out as described in General Procedure 9 using a 25 g silica column eluted with a 0 to 50% DCM / MeOH gradient to give the Boc-protected intermediate as a red solid. This material was then deprotected according to General Procedure 6, followed by preparative HPLC purification as described in General Procedure 9, eluting with a 20 to 65% CHCN / H0+0.1% TFA gradient, to afford the title compound as a red solid (TFA salt, 300 mg, 53% yield).

[0689] LC / MS:C 21 H 19 Calculated m / z for N3O5 = 393.2, observed [M+H] + =393.2.

[0690] 1 H NMR (300 MHz, MeOD) δ 8.27 (s, 1H), 7.62 (s, 1H), 7.42 (s, 1H), 7.11 (s, 1H), 5.61 (d, J = 16.2 Hz, 1H), 5.38 (d, J = 16.2 Hz, 1H), 5.24 (s, 2H), 4.11 (s, 3H), 2.06 - 1.91 (m, 2H), 1.04 (t, J = 7.4 Hz, 3H).

[0691] 3.42: 5-Bromo-2-nitro-4-(trifluoromethyl)benzaldehyde (compound 3.42) [ka] To a stirred solution of HNO (2.0 g, 1.4 mL, 67% purity, 2 equiv.) in HSO (8 mL) at 0 °C was added 3-bromo-4-(trifluoromethyl)benzaldehyde (4 g, 1 equiv.). After the addition was complete, the ice bath was removed and the reaction was stirred at room temperature for 5 h. The mixture was poured onto ice (100 mL) and the precipitate was extracted with DCM (3 × 100 mL). The combined organic fractions were then washed with brine (50 mL), dried over NaSO, and concentrated in vacuo to afford the title compound as a yellow solid (4.4 g, 93% yield).

[0692] LC / MS: m / z calculated for C8H3BrF3NO3 = 296.90, found [M+H] + =298.0.

[0693] 1 H NMR (300 MHz, MeOD) δ 10.35 (s, 1H), 8.29 (s, 1H), 8.23 ​​(s, 1H).

[0694] 3.43: tert-Butyl (5-formyl-4-nitro-2-(trifluoromethyl)phenyl)carbamate (compound 3.43) [ka] A mixture of compound 3.42 (800 mg, 1 equiv.), tert-butyl carbamate (378 mg, 1.2 equiv.), CsCO (1.7 g, 2 equiv.), Pd(dba) (122 mg, 0.05 equiv.), and dicyclohexyl[2',4',6'-tris(propan-2-yl)[1,1'-biphenyl]-2-yl]phosphane (XPhos) (256 mg, 0.2 equiv.) in toluene (5 mL) was degassed and purged with N for three cycles. The mixture was then stirred at 90 °C under a N atmosphere for 15 h. The reaction mixture was diluted with HO (25 mL) and extracted with EtOAc (3 × 50 mL). The combined organic layers were washed with brine (2 × 25 mL), dried over sodium sulfate, filtered, and concentrated under reduced pressure. Flash purification was carried out using a 25 g silica column according to general procedure 9, eluting with 0 to 25% DCM / MeOH to give the title compound as an orange solid (750 mg, 84% yield).

[0695] LC / MS:C 13 H 13 Calculated m / z for FN2O5 = 334.1, measured [MH] - =333.1.

[0696] 3.44: tert-Butyl (4-amino-5-formyl-2-(trifluoromethyl)phenyl)carbamate (compound 3.44) [ka] To a solution of compound 3.43 (750 mg, 1 equiv.) in MeOH (16 mL) and HO (1.6 mL) was added B(OH) (603 mg, 3 equiv.). The resulting mixture was cooled to 0 °C, and 5 M aqueous NaOH (2.75 mL) was added with stirring over 10 min. The reaction mixture was stirred for an additional 5 min, and then quenched by pouring the solution onto ice (50 mL). The resulting mixture was extracted with DCM (3 × 75 mL), dried over sodium sulfate, filtered, and concentrated in vacuo. Flash purification was performed as described in General Procedure 9 using a 25 g silica column eluting with 10 to 50% hexanes / EtOAc to afford the title compound as an orange solid (460 mg, 67%).

[0697] LC / MS:C 13 H 15 Calculated m / z for F3N2O3 = 304.1, observed [M+H] + =305.2.

[0698] 3.45: (S)-9-Amino-4-ethyl-4-hydroxy-8-(trifluoromethyl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H)-dione (compound 167) [ka] A mixture of compound 3.44 (460 mg, 1 equiv.) and (S)-4-ethyl-4-hydroxy-7,8-dihydro-1H-pyrano[3,4-f]indolizine-3,6,10(4H)-trione (378 mg, 0.95 equiv.), TsOH (monohydrate, 26 mg, 0.1 equiv.), and toluene (35 mL) in a 250 mL round-bottom flask equipped with a Dean-Stark apparatus was stirred at 110° C. for 2 hours. The reaction mixture was then cooled to 25° C. and concentrated under reduced pressure. Purification was carried out as described in General Procedure 9 using a 25 g silica column eluted with a 0 to 50% DCM / MeOH gradient to give the Boc-protected intermediate as a red solid. This material was then deprotected according to General Procedure 6, followed by preparative HPLC purification as described in General Procedure 9, eluting with a 20 to 65% CHCN / H0+0.1% TFA gradient, to afford the title compound as a yellow solid (6.2 mg, 48%).

[0699] LC / MS:C 21 H 16 Calculated m / z for F3N3O4 = 431.1, found [M+H] + =432.2.

[0700] 1 H NMR (300 MHz, MeOD) δ 8.29 (s, 1H), 8.27 (s, 1H), 7.59 (s, 1H), 7.24 (s, 1H), 5.59 (d, J = 16.3 Hz, 1H), 5.39 (d, J = 16.3 Hz, 1H), 5.28 (s, 2H), 2.00 - 1.89 (m, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0701] Example 4: Preparation of Drug-Linker 4.1: 2,5-Dioxopyrrolidin-1-yl(((9H-fluoren-9-yl)methoxy)carbonyl)glycylglycinate (compound 4.1) [ka] The title compound was prepared according to the procedure described in Chinese Patent Publication No. CN105218644.

[0702] 4.2: (((9H-Fluoren-9-yl)methoxy)carbonyl)glycylglycyl-L-phenylalanine (Fmoc-GGF-OH; compound 4.2) [ka] To L-phenylalanine (965 mg) in acetonitrile (10 mL) and dimethylformamide (0.5 mL) was added DIPEA (1.51 mL), followed by compound 4.1 (1.3 g). After 1 h, the reaction was concentrated to dryness. Flash purification was performed as described in General Procedure 9, eluting with a 10 to 50% CHCN / HO + 0.1% TFA gradient, to afford the title compound as a white solid (430 mg, 30% yield).

[0703] LC / MS:C 28 H 71 Calculated m / z for N3O6S = 501.2, observed [M+H] + =502.4.

[0704] 1 H NMR (300 MHz, DMSO) δ 8.16 (d, J = 8.1 Hz, 1H), 8.04 (t, J = 5.8 Hz, 1H), 7.90 (d, J = 7.5 Hz, 2H), 7.72 (d, J = 7.4 Hz, 2H), 7.59 (t, J = 6.0 Hz, 1H), 7.54 - 7.39 (m, 2H), 7.33 (t, J = 7.6 Hz, 2H), 7.28 - 7.13 (m, 5H), 4.44 (td, J = 8.5, 5.1 Hz, 1H), 4.33 - 4.13 (m, 3H), 3.83 - 3.59 (m, 4H), 3.06 (dd, J = 13.7, 5.1 Hz, 1H), 2.88 (dd, J = 13.8, 9.0 Hz, 1H).

[0705] 4.3: 2,3,5,6-tetrafluorophenyl 3-(2-(2-(2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)ethoxy)ethoxy)ethoxy)propanoate (MT-OTfp; compound 4.3) [ka] The title compound was prepared according to the procedures described in International (PCT) Publication No. WO2017 / 054080.

[0706] 4.4: (3-(2-(2-(2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)ethoxy)ethoxy)ethoxy)propanoyl)glycylglycyl-L-phenylalanine (compound 4.4) [ka] To a solution of compound 4.3 (1.61 g, 3.58 mmol) in DMF (35 mL) was added Gly-Gly-Phe (1 g, 3.58 mmol) in one portion, followed by iPrNEt (1.25 mL, 7.2 mmol). The solution was stirred at room temperature for 1 h and then evaporated to dryness. Purification was carried out as described in General Procedure 9 using a 30 g C flash column eluted with a 10 to 90% CHCN / HO + 0.1% TFA gradient to afford the title compound as a white solid (400 mg, 20% yield).

[0707] LC / MS:C 26 H 34 N4O 10 Calculated value for m / z=562.6, measured value [MH] - =561.5.

[0708] 1H NMR (300 MHz, CDCl3) δ 7.60 (t, J = 5.6 Hz, 2H), 7.41 (d, J = 7.7 Hz, 1H), 7.32 - 7.07 (m, 5H), 6.70 (s, 2H), 6.33 - 6.07 (m, 3H), 4.72 (td, J = 7.6, 5.3 Hz, 1H), 4.12 - 3.78 (m, 4H), 3.72 (ddd, J = 15.2, 6.9, 4.8 Hz, 5H), 3.60 (dd, J = 11.6, 6.1 Hz, 10H), 3.12 (ddd, J = 48.2, 14.0, 6.5 Hz, 2H), 2.52 (d, J = 11.7 Hz, 2H).

[0709] 4.5: (S)-11-benzyl-1-(9H-fluoren-9-yl)-3,6,9,12,15-pentaoxo-2-oxa-4,7,10,13,16-pentaazaheptadecan-17-yl acetate (compound 4.5) [ka] The title compound was prepared according to the procedures described in U.S. Patent Publication No. US2017 / 021031.

[0710] 4.6: (S)-11-benzyl-1-(9H-fluoren-9-yl)-3,6,9,12,15-pentaoxo-2-oxa-4,7,10,13,16-pentaazaheptadecan-17-yl acetate (compound 4.6) [ka] The title compound was prepared according to the procedure described in US Patent Publication No. US2017 / 021031 using Fmoc-GGFGG-OH as the starting peptide.

[0711] 4.7: tert-Butyl (2-((2-(((S)-1-((2-((4-((4-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)piperazin-1-yl)sulfonyl)phenyl)amino)-2-oxoethyl)amino)-1-oxo-3-phenylpropan-2-yl)amino)-2-oxoethyl)amino)-2-oxoethyl)carbamate (compound 4.7) [ka] The title compound was prepared according to general procedure 7 starting from compound 104 (20 mg). Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as a white solid (14 mg, 42% yield).

[0712] LC / MS:C 52 H 58 N9O 12 Calculated m / z for S = 1051.4, observed [M+H] + =1052.6.

[0713] 4.8: (S)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecan-18-amide)-N-(2-((4-((4-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)piperazin-1-yl)sulfonyl)phenyl)amino)-2-oxoethyl)-3-phenylpropanamide (MT-GGFG-Compound 104) [ka] The title compound was prepared starting from compound 4.7 (14 mg) according to procedure 6 followed by procedure 8. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as a white solid (9.1 mg, 56% yield).

[0714] LC / MS:C 60 H 67 FN 10 O 16 Calculated m / z for S = 1234.4, observed [M+H] + =1235.8.

[0715] 4.9: tert-Butyl (2-((2-(((S)-1-((2-((4-(4-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)piperazin-1-yl)phenyl)amino)-2-oxoethyl)amino)-1-oxo-3-phenylpropan-2-yl)amino)-2-oxoethyl)amino)-2-oxoethyl)carbamate (compound 4.9) [ka] The title compound was prepared according to general procedure 7 starting from compound 108 (12 mg). Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as a white solid (13 mg, 62% yield).

[0716] LC / MS:C 52 H 58 N9O 10 Calculated value m / z=987.4, observed value [M+H] + =988.6.

[0717] 4.10: (S)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecan-18-amide)-N-(2-((4-(4-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)piperazin-1-yl)phenyl)amino)-2-oxoethyl)-3-phenylpropanamide (MT-GGFG-Compound 108) [ka] The title compound was prepared starting from compound 4.9 (13 mg) according to procedure 6 followed by procedure 8. Preparative HPLC purification was performed as described in general procedure 9, eluting with a 10 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as a white solid (3.1 mg, 20% yield).

[0718] LC / MS:C 60 H 67 FN 10 O 14 Calculated value for m / z=1170.5, observed value [M+H] + =1171.6.

[0719] 4.11: (9H-Fluoren-9-yl)methyl (S)-(1-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)-3,10-dioxo-7-oxa-2,4,9-triazaundecan-11-yl)carbamate (compound 4.11) [ka] To a solution of compound 1.2 (31 mg, 0.076 mmol) in DMF (750 μL) was added (9H-fluoren-9-yl)methyl (2-(((2-(((4-nitrophenoxy)carbonyl)amino)ethoxy)methyl)amino)-2-oxoethyl)carbamate (41 mg, 0.076 mmol), followed by iPrNEt (26 μL, 0.15 mmol). The solution was stirred at room temperature for 2 hours and then applied directly to a 12 g C column. Purification was carried out as described in General Procedure 9, eluting with a 10-100% CHCN / HO + 0.1% TFA gradient to afford the title compound as a white solid (21 mg, 35% yield).

[0720] LC / MS:C 43 H 41 Calculated m / z for FN6O9 = 804.87, found [M+H] + =805.6.

[0721] 4.12: (S)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecan-18-amide)-N-(1-((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)-3,10-dioxo-7-oxa-2,4,9-triazaundecan-11-yl)-3-phenylpropanamide (MT-GGFG-AM-Compound 136) [ka] Compound 4.11 (21 mg, 0.026 mmol) was dissolved in a 10% solution of piperidine in DMF (1 mL) and stirred for 10 min. The piperidine solution was evaporated, and the resulting residue was redissolved in DMF (5 mL) and evaporated to dryness again. To this residue was added DMF (50 μL) and DCM (450 μL), followed by compound 4.4 (15 mg, 0.026 mmol), NMM (10 μL), and HATU (10 mg, 0.026 mmol). Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 30-60% CHCN / HO + 0.1% TFA gradient, to afford the title compound as a yellow solid (7.6 mg, 26% yield).

[0722] LC / MS:C 54 H 63 FN 10 O 16 Calculated value for m / z=1127.1, observed value [M+H] + =1128.2.

[0723] 4.13: (9H-Fluoren-9-yl)methyl(2-(((2-(chlorosulfonyl)ethoxy)methyl)amino)-2-oxoethyl)carbamate (compound 4.13) [ka] To a solution of compound 4.5 (50 mg, 0.14 mmol) in DCM (800 μL) was added 2-hydroxyethane-1-sulfonyl chloride (100 mg, 0.7 mmol), followed by TFA (200 μL). The solution was stirred at room temperature for 30 minutes and then evaporated to dryness. Purification was carried out as described in General Procedure 9 using a 10 g silica column eluted with a 10 to 100% EtOAc / hexane gradient to afford the title compound (31 mg, 50% yield) as a clear film.

[0724] LC / MS:C 20 H 21 Calculated m / z for ClN2O6S = 452.1, found [M+Na] + =472.9.

[0725] 4.14: (9H-Fluoren-9-yl)methyl (S)-(2-(((2-(N-((4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)sulfamoyl)ethoxy)methyl)amino)-2-oxoethyl)carbamate (compound 4.14) [ka] The title compound was prepared as described in General Procedure 3 using compound 1.2 (28 mg, 0.07 mmol) and compound 4.13 (31 mg, 0.07 mmol). Purification was carried out as described in General Procedure 9 using a 12 g C18 column eluted with a 10 to 100% CHCN / HO + 0.1% TFA gradient to afford the title compound as a yellow solid (22 mg, 39% yield).

[0726] LC / MS:C 42 H 40 FN5O 10 Calculated m / z for S = 825.9, observed [M+H] + =826.7.

[0727] 4.15: (S)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecan-18-amide)-N-(2-(((2-(N-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)sulfamoyl)ethoxy)methyl)amino)-2-oxoethyl)-3-phenylpropanamide (MT-GGFG-AM-Compound 129) [ka] Compound 4.14 (22 mg, 0.027 mmol) was dissolved in a 10% solution of piperidine in DMF (1 mL) and stirred for 10 min. The piperidine solution was evaporated, and the resulting residue was redissolved in DMF (5 mL) and evaporated to dryness again. To this residue was added DMF (50 μL) and DCM (450 μL), followed by compound 4.4 (30 mg, 0.053 mmol), NMM (10 μL), and HATU (18 mg, 0.048 mmol). Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 30-60% CHCN / HO + 0.1% TFA gradient, to afford the title compound as a yellow solid (6.4 mg, 21% yield).

[0728] LC / MS:C 53 H 62 FN9O 17 Calculated m / z for S = 1148.2, observed [M+H] + =1148.6.

[0729] 1 H NMR (300 MHz, MeOD) δ 8.60 (t, J = 6.5 Hz, 1H), 8.36 (t, J = 8.6 Hz, 2H), 8.13 (d, J = 6.6 Hz, 1H), 7.77 (d, J = 10.6 Hz, 1H), 7.65 (d, J = 4.8 Hz, 1H), 7.28 - 7.00 (m, 6H), 6.80 (s, 2H), 5.69 - 5.50 (m, 3H), 5.45 - 5.33 (m, 2H), 4.44 (dd, J = 8.7, 5.7 Hz, 1H), 3.96 (t, J = 5.3 Hz, 2H), 3.90 - 3.76 (m, 5H), 3.76 - 3.57 (m, 7H), 3.09 - 2.81 (m, 3H), 2.61 - 2.45 (m, 5H), 2.04 - 1.90 (m, 2H), 1.03 (t, J = 7.3 Hz, 3H).

[0730] 4.16: (9H-Fluoren-9-yl)methyl (S)-(2-(((morpholin-2-ylmethoxy)methyl)amino)-2-oxoethyl)carbamate (compound 4.16) [ka] To a solution of compound 4.5 (100 mg, 0.27 mmol) in DCM (800 μL) was added (S)-morpholin-2-ylmethanol (160 mg, 1.36 mmol), followed by TFA (200 μL). The solution was stirred at room temperature for 1 hour and then evaporated to dryness. Purification was carried out as described in General Procedure 9 using a 12 g C18 flash column eluted with a 10 to 90% CH3CN / HO + 0.1% TFA gradient to afford the title compound as a yellow solid (TFA salt, 105 mg, 72% yield).

[0731] LC / MS:C 23 H 27 Calculated m / z for N3O5 = 425.2, observed [M+Na] + =448.0.

[0732] 4.17: (9H-Fluoren-9-yl)methyl (2-(((((S)-4-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)morpholin-2-yl)methoxy)methyl)amino)-2-oxoethyl)carbamate (compound 4.17) [ka] The title compound was prepared according to general procedure 1 starting from compound 1.1 (50 mg, 0.117 mmol) and compound 4.16 (63 mg, 0.117 mmol). Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 100% CHCN / HO + 0.1% TFA gradient to afford the title compound as an off-white solid (TFA salt, 33 mg, 35% yield).

[0733] LC / MS:C 45 H 44 Calculated m / z for FN5O9 = 817.9, observed [M+H] + =818.7.

[0734] 4.18: (S)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecan-18-amide)-N-(2-(((((S)-4-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)morpholin-2-yl)methoxy)methyl)amino)-2-oxoethyl)-3-phenylpropanamide (MT-GGFG-AM-Compound 113) [ka] Compound 4.17 (33 mg, 0.04 mmol) was dissolved in a 10% solution of piperidine in DMF (1 mL) and stirred for 10 minutes. The piperidine solution was evaporated, and the resulting residue was redissolved in DMF (5 mL) and evaporated to dryness again. To this residue was added DMF (100 μL) and DCM (900 μL), followed by compound 4.4 (45 mg, 0.08 mmol), NMM (20 μL), and HATU (28 mg, 0.073 mmol). Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 30-60% CHCN / HO + 0.1% TFA gradient, to afford the title compound as a yellow solid (22 mg, 48% yield).

[0735] LC / MS:C 56 H 66 FN9O 16 Calculated value for m / z=1140.2, observed value [M+H] + =1141.1.

[0736] 1H NMR (300 MHz, MeOD) δ 8.35 (d, J = 7.5 Hz, 2H), 7.74 - 7.61 (m, 1H), 7.53 (s, 1H), 7.34 - 7.10 (m, 6H), 6.81 (s, 2H), 5.65 - 5.30 (m, 4H), 4.64 (t, J = 3.4 Hz, 2H), 4.42 (tt, J = 6.3, 2.5 Hz, 1H), 4.09 (d, J = 12.3 Hz, 1H), 3.98 - 3.76 (m, 8H), 3.72 (t, J = 6.0 Hz, 2H), 3.69 - 3.44 (m, 17H), 3.21 - 2.85 (m, 3H), 2.64 - 2.42 (m, 5H), 2.03 - 1.84 (m, 2H), 0.98 (t, J = 7.3 Hz, 3H).

[0737] 4.19: (9H-Fluoren-9-yl)methyl (S)-(2-((((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methoxy)methyl)amino)-2-oxoethyl)carbamate (compound 4.19) [ka] Compound 3.5 (55 mg, 0.11 mmol) was dissolved in TFA (500 μL) and stirred at room temperature for 20 minutes. Then, hexafluoroisopropanol (2 mL) was added, followed by compound 4.5 (40 mg, 0.11 mmol). The solution was stirred at room temperature for approximately 16 hours and then concentrated to dryness. Purification was carried out as described in General Procedure 9 using a 12 g C18 flash column eluted with a 10-50% CH3CN / HO + 0.1% TFA gradient to afford the title compound (11 mg, 14% yield) as a yellow solid.

[0738] LC / MS:C 39 H 34 Calculated m / z for FN5O8 = 719.7, observed [M+H]+ =720.6.

[0739] 4.20: (S)-N-(2-(((((S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methoxy)methyl)amino)-2-oxoethyl)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecane-18-amido)-3-phenylpropanamide (MT-GGFG-AM-Compound 141) [ka] Compound 4.19 (11 mg, 0.015 mmol) was dissolved in a 10% solution of piperidine in DMF (1 mL) and stirred for 10 minutes. The piperidine solution was evaporated, and the resulting residue was redissolved in DMF (5 mL) and evaporated to dryness again. To this residue was added DMF (50 μL) and DCM (450 μL), followed by compound 4.4 (26 mg, 0.045 mmol), NMM (5 μL), and HATU (18 mg, 0.045 mmol). Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 32-45% CHCN / HO + 0.1% TFA gradient, to afford the title compound as a yellow solid (4.6 mg, 29% yield).

[0740] LC / MS:C 50 H 56 FN9O 15 Calculated value for m / z=1142.0, observed value [M+H] + =1143.1.

[0741] 1H NMR (300 MHz, MeOD) δ 8.36 (s, 1H), 8.28 (d, J = 6.1 Hz, 1H), 8.16 (dd, J = 20.1, 6.8 Hz, 3H), 7.59 - 7.44 (m, 2H), 7.31 - 7.08 (m, 6H), 6.79 (s, 2H), 5.58 (d, J = 16.1 Hz, 1H), 5.37 (d, J = 16.1 Hz, 1H), 5.30 - 5.16 (m, 3H), 4.56 - 4.39 (m, 1H), 4.07 - 3.90 (m, 2H), 3.85 (dt, J = 11.5, 5.4 Hz, 4H), 3.79 - 3.67 (m, 4H), 3.67 - 3.55 (m, 7H), 3.54 (d, J = 6.5 Hz, 8H), 3.10 (dd, J = 14.0, 6.1 Hz, 1H), 2.92 (dd, J = 13.9, 9.1 Hz, 1H), 2.53 (t, J = 6.0 Hz, 2H), 1.98 (q, J = 7.2 Hz, 2H), 1.31 (s, 1H), 1.04 (t, J = 7.3 Hz, 3H).

[0742] 4.21: N-((S)-1-((S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)-9-benzyl-5,8,11,14-tetraoxo-2-oxa-4,7,10,13-tetraazapentadecan-15-yl)-6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanamide (MC-GGFG-AM-Compound 141) [ka] Compound 4.19 (25 mg, 0.035 mmol) was dissolved in a 10% solution of piperidine in DMF (1 mL) and stirred for 10 minutes. The piperidine solution was evaporated, and the resulting residue was redissolved in DMF (5 mL) and evaporated to dryness again. To this residue was added DMF (50 μL) and DCM (450 μL), followed by MC-GGF-OH (33 mg, 0.07 mmol), NMM (20 μL), and HATU (25 mg, 0.066 mmol). Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 30-50% CHCN / HO + 0.1% TFA gradient, to afford the title compound as a yellow solid (4.3 mg, 13% yield).

[0743] LC / MS:C 47 H 50 FN9O 12 Calculated value for m / z=952.0, observed value [M+H] + =952.9.

[0744] 1 H NMR (300 MHz, CD3CN) δ 7.96 - 7.72 (m, 1H), 7.39 - 7.07 (m, 8H), 6.94 (d, J = 9.1 Hz, 1H), 6.73 (s, 2H), 5.44 (d, J = 16.2 Hz, 1H), 5.25 (d, J = 16.2 Hz, 1H), 5.06 (d, J = 4.4 Hz, 2H), 4.81 (d, J = 26.1 Hz, 4H), 4.61 (s, 1H), 3.96 (s, 1H), 3.77 (d, J = 8.1 Hz, 7H), 3.02 (d, J = 5.6 Hz, 5H), 2.19 (t, J = 7.7 Hz, 3H), 1.50 (dp, J = 14.8, 7.4 Hz, 6H), 1.32 - 1.12 (m, 3H), 0.96 (t, J = 7.2 Hz, 3H).

[0745] 4.22: tert-butyl (2-((2-(((S)-1-((2-(((S)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)amino)-1-oxo-3-phenylpropan-2-yl)amino)-2-oxoethyl)amino)-2-oxoethyl)carbamate (compound 4.22) [ka] The title compound was prepared according to Procedure 7 starting from compound 140 (28 mg). Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 10 to 50% CHCN / HO+0.1% TFA gradient to afford the title compound as a white solid (10 mg, 17% yield).

[0746] LC / MS:C 40 H 42 N7O 10 Calculated value for m / z=799.3, observed value [M+H] + =800.6.

[0747] 4.23: (S)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecan-18-amido)-N-(2-(((S)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)-3-phenylpropanamide (MT-GGFG-Compound 140) [ka] The title compound was prepared starting from compound 4.22 (10 mg) according to general procedure 6 followed by general procedure 8. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as a white solid (6.8 mg, 55% yield).

[0748] LC / MS:C 48 H 51 FN8O 14 Calculated value for m / z=982.4, observed value [M+H] + =983.6.

[0749] 4.24: tert-butyl (2-((2-(((S)-1-((2-(((S)-4-ethyl-8-fluoro-4-hydroxy-11-(morpholinomethyl)-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)amino)-1-oxo-3-phenylpropan-2-yl)amino)-2-oxoethyl)amino)-2-oxoethyl)carbamate (compound 4.24) [ka] The title compound was prepared according to general procedure 7 starting from compound 142 (TFA salt, 45 mg). Purification was carried out as described in general procedure 9 using a 12 g C18 flash column eluted with a 10 to 50% CH3CN / HO + 0.1% TFA gradient to afford the title compound as a white solid (13 mg, 22% yield).

[0750] LC / MS:C 45 H 51 N8O 11 Calculated value for m / z=898.4, observed value [M+H] + =899.6.

[0751] 4.25: (S)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecan-18-amide)-N-(2-(((S)-4-ethyl-8-fluoro-4-hydroxy-11-(morpholinomethyl)-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)-3-phenylpropanamide (MT-GGFG-Compound 142) [ka] The title compound was prepared starting from compound 4.24 (13 mg) according to general procedure 6 followed by general procedure 8. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as a white solid (2.6 mg, 17% yield).

[0752] LC / MS:C 53 H 60 FN9O 15 Calculated value for m / z=1081.4, observed value [M+H] + =1082.6.

[0753] 1H NMR (300 MHz, MeOD) δ 9.34 (d, J = 8.5 Hz, 1H), 7.87 (d, J = 11.8 Hz, 1H), 7.62 (s, 1H), 7.33 - 7.19 (m, 5H), 6.80 (s, 2H), 5.62 (d, J = 16.3 Hz, 1H), 5.51 (s, 2H), 5.47 - 5.35 (m, 3H), 4.73 (dd, J = 9.6, 5.1 Hz, 1H), 4.61 (s, 3H), 4.30 - 4.15 (m, 2H), 4.11 (s, 2H), 4.00 - 3.82 (m, 4H), 3.82 - 3.70 (m, 7H), 3.70 - 3.50 (m, 13H), 3.18 - 3.04 (m, 1H), 2.88 (s, 1H), 2.64 (d, J = 5.8 Hz, 4H), 2.54 (t, J = 6.0 Hz, 2H), 2.09 - 1.92 (m, 2H), 1.03 (t, J = 7.3 Hz, 3H).

[0754] 4.26: (9H-Fluoren-9-yl)methyl (S)-(12-benzyl-1-(4-nitrophenoxy)-1,8,11,14,17-pentaoxo-2,5-dioxa-7,10,13,16-tetraazaoctadecan-18-yl)carbamate (compound 4.26) [ka] To a stirred solution of compound 4.6 (60 mg) in dichloromethane (2 mL) was added ethylene glycol (100 μL), followed by trifluoroacetic acid (0.4 mL). After 30 minutes, the reaction was concentrated in vacuo. Purification of the intermediate compound was carried out as described in General Procedure 9 using a 10 g flash column eluting with a 0 to 20% dichloromethane / methanol gradient. To the purified intermediate in tetrahydrofuran (0.5 mL) was added bis-nitrophenol carbonate (58 mg), followed by DIPEA (50 μL). The solution was stirred for 16 hours, quenched with acetic acid (approximately 100 μL), and then concentrated to dryness. Purification was carried out as described in General Procedure 9 using a 10 g flash column eluting with a 0 to 20% dichloromethane / methanol gradient to afford the title compound as a white solid (40 mg, 53% yield from compound 4.6).

[0755] LC / MS:C 40 H 40 NO 12 Calculated value for m / z=796.3, observed value [M+Na] + =819.4.

[0756] 4.27: (S)-16-Amino-10-benzyl-6,9,12,15-tetraoxo-3-oxa-5,8,11,14-tetraazahexadecyl (((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamate (compound 4.27) [ka] To a solution of compound 4.26 (40 mg) in dimethylformamide (1 mL) was added DIPEA (26 μL), followed by a solution of compound 1.2 (24 mg) in dimethylformamide (0.5 mL). The solution was stirred at room temperature for 4 hours, then quenched with 20% piperidine in dimethylformamide solution (0.5 mL) and stirred for an additional 20 minutes. Purification was carried out as described in General Procedure 9 using a 12 g C18 flash column eluted with a 10 to 50% CH3CN / HO + 0.1% TFA gradient to afford the title compound as a white solid (TFA salt, 19 mg, 39% yield).

[0757] LC / MS:C 41 H 45 FN8O 11 Calculated value for m / z=844.3, observed value [M+H] + =845.6.

[0758] 4.28: (S)-10-benzyl-29-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-6,9,12,15,18-pentaoxo-3,21,24,27-tetraoxa-5,8,11,14,17-pentaazanonacosyl (((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamate (MT-GGFG-AM-Compound 139) [ka] The title compound was prepared according to general procedure 8 starting from compound 4.27 (10 mg). Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as a white solid (8.8 mg, 75% yield).

[0759] LC / MS:C 54 H 62 FN9O 17Calculated value for m / z=1127.4, observed value [M+H] + =1128.6.

[0760] 1 H NMR (300 MHz, MeOD) δ 8.27 (d, J = 8.1 Hz, 1H), 7.81 (d, J = 10.7 Hz, 1H), 7.65 (s, 1H), 7.32 - 7.16 (m, 5H), 6.81 (s, 2H), 5.62 (d, J = 16.4 Hz, 1H), 5.53 (s, 2H), 5.42 (d, J = 16.4 Hz, 1H), 4.93 (s, 2H), 4.67 (s, 1H), 4.51 (dd, J = 9.3, 5.6 Hz, 1H), 4.18 (t, J = 4.7 Hz, 2H), 4.01 - 3.44 (m, 19H), 3.17 (dd, J = 13.9, 5.8 Hz, 1H), 2.97 (dd, J = 13.9, 9.0 Hz, 1H), 2.57 (s, 3H), 2.52 (t, J = 6.0 Hz, 2H), 2.03 - 1.91 (m, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0761] 4.29: (S)-2-Amino-N-(4-ethyl-8-fluoro-4-hydroxy-11-(hydroxymethyl)-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)acetamide (compound 4.29) [ka] To a stirred solution of Fmoc-glycine (217 mg) in dimethylformamide (2.5 mL) was added HATU (254 mg), HOAt (83 mg), and then NMM (188 μL). After stirring for 10 minutes, compound 141 (50 mg) was added and the reaction was stirred at room temperature for 16 hours. Lithium hydroxide (2.5 mL, 1 M in water) was added and the reaction mixture was stirred for 2 hours. After partially concentrating the solution, a 20% solution of piperidine in dimethylformamide (0.5 mL) was added and stirred for an additional 20 minutes. The reaction was then evaporated onto Celite and purified as described in General Procedure 9 using a 12 g C18 flash column eluting with a 0 to 40% CH3CN / HO + 0.1% TFA gradient to afford the title compound as a white solid (TFA salt, 44 mg, 62% yield).

[0762] LC / MS:C 23 H 21 Calculated m / z for FN4O6 = 468.1, observed [M+H] + =469.4.

[0763] 1 H NMR (300 MHz, MeOD) δ 8.99 (d, J = 8.3 Hz, 1H), 7.99 (s, 1H), 7.87 (d, J = 12.0 Hz, 1H), 7.55 (s, 1H), 5.60 (d, J = 16.3 Hz, 1H), 5.46 - 5.35 (m, 3H), 5.30 (s, 2H), 3.53 - 3.45 (m, 1H), 3.43 - 3.38 (m, 1H), 2.03 - 1.87 (m, 2H), 1.02 (t, J = 7.3 Hz, 3H).

[0764] 4.30: (S)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecan-18-amido)-N-(2-(((S)-4-ethyl-8-fluoro-4-hydroxy-11-(hydroxymethyl)-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)-3-phenylpropanamide (MT-GGFG-Compound 141) [ka] To a stirred solution of compound 4.4 (23 mg) in a mixture of dimethylformamide (0.1 mL) and dichloromethane (0.9 mL) was added HATU (14 mg), a solution of compound 4.29 (20 mg) in dimethylformamide (0.1 mL) and dichloromethane (0.9 mL), and DIPEA (24 μL). After stirring the mixture for 15 minutes, the reaction was partially concentrated. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 0 to 40% CHCN / HO + 0.1% TFA gradient, to afford the title compound as a white solid (7.1 mg, 20% yield).

[0765] LC / MS:C 49 H 53 FN8O 15 Calculated value for m / z=1012.4, observed value [M+H] + =1013.6.

[0766] 1H NMR (300 MHz, MeOD) δ 9.89 (s, 1H), 8.75 (d, J = 8.3 Hz, 1H), 8.44 - 8.32 (m, 1H), 8.27 - 8.14 (m, 2H), 7.78 (d, J = 11.9 Hz, 1H), 7.53 (s, 1H), 7.39 - 7.20 (m, 5H), 6.82 (s, 2H), 5.57 (d, J = 16.3 Hz, 1H), 5.39 (d, J = 16.3 Hz, 1H), 5.34 - 5.25 (m, 2H), 5.22 (s, 2H), 4.32 - 4.09 (m, 2H), 3.96 - 3.83 (m, 3H), 3.76 (t, J = 6.0 Hz, 2H), 3.69 - 3.62 (m, 2H), 3.62 - 3.47 (m, 9H), 3.40 - 3.33 (m, 1H), 3.08 (dd, J = 14.0, 9.6 Hz, 1H), 2.56 (t, J = 6.1 Hz, 2H), 2.03 - 1.91 (m, 2H), 1.04 (t, J = 7.3 Hz, 3H).

[0767] 4.31: tert-Butyl (S)-((9-amino-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamate (compound 4.31) [ka] To a stirred solution of compound 145 (32 mg) in dichloromethane (2 mL) and acetonitrile (0.5 mL) was added di-tert-butyl dicarbonate (20 μL), followed by DIPEA (42 μL). The reaction mixture was stirred at room temperature for 3 hours and then concentrated to dryness to give the title compound (34 mg, 87%) as a red solid.

[0768] LC / MS:C 26 H 27 Calculated m / z for FN4O6 = 510.2, observed [M+H]+ =511.2.

[0769] 4.32: tert-Butyl (S)-((9-(2-aminoacetamido)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamate (compound 4.32) [ka] To a stirred solution of Fmoc-glycine (98 mg) in dimethylformamide (1 mL) was added HATU (115 mg), HOAt (37 mg), and then NMM (85 μL). The solution was stirred for 10 minutes, after which compound 4.31 (28 mg) was added. The reaction was stirred at room temperature for 16 hours, then quenched with a 20% solution of piperidine in dimethylformamide (1 mL) and stirred for an additional 20 minutes. Purification was carried out as described in General Procedure 9 using a 12 g C18 flash column eluting with a 5-40% CH3CN / HO + 0.1% TFA gradient to afford the title compound as a white solid (TFA salt, 25 mg, 67% yield).

[0770] LC / MS:C 28 H 30 Calculated m / z = 567.2 for FN6O7, measured value [M+H] + =568.4.

[0771] 1 H NMR (300 MHz, MeOD) δ 9.01 (d, J = 8.3 Hz, 1H), 7.83 (d, J = 11.9 Hz, 1H), 7.52 (s, 1H), 5.57 (d, J = 16.4 Hz, 1H), 5.38 (d, J = 16.3 Hz, 1H), 5.27 (d, J = 3.1 Hz, 2H), 4.80 (s, 2H), 4.10 (s, 2H), 1.97 (q, J = 7.4 Hz, 2H), 1.50 (s, 9H), 1.02 (t, J = 7.3 Hz, 3H).

[0772] 4.33: tert-Butyl (((S)-9-(2-((S)-2-(2-(2-aminoacetamido)acetamido)-3-phenylpropanamido)acetamido)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamate (compound 4.33) [ka] To a stirred solution of Fmoc-GGF-OH (28 mg) and HATU (20 mg) in a mixture of DMF (0.2 mL) and dichloromethane (1.8 mL) was added compound 4.32 (25 mg), followed by DIPEA (32 μL). The solution was stirred at room temperature for 15 minutes, quenched with a 20% solution of piperidine in dimethylformamide (0.250 mL), stirred for an additional 20 minutes, and then partially concentrated in vacuo. Purification was carried out as described in General Procedure 9 using a 12 g C18 flash column eluted with a 10 to 45% CH3CN / HO + 0.1% TFA gradient to afford the title compound as a white solid (TFA salt, 22 mg, 64% yield).

[0773] LC / MS:C 41 H 45 FN8O 10 Calculated value for m / z=828.3, observed value [M+H] + =829.6.

[0774] 4.34: (S)-N-(2-(((S)-11-(aminomethyl)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecane-18-amido)-3-phenylpropanamide (MT-GGFG-Compound 145) [ka] The title compound was prepared starting from compound 4.33 (15 mg) according to procedure 6 followed by procedure 8. Preparative HPLC purification of the intermediate Boc-protected compound was performed as described in general procedure 9, eluting with a 10 to 50% CHCN / HO+0.1% TFA gradient. The title compound was obtained as a white solid after Boc-deprotection (TFA salt, 8.5 mg, 52% yield).

[0775] LC / MS:C 49 H 53 FN8O 15 Calculated value for m / z=1011.4, observed value [M+H] + =1012.6.

[0776] 1 H NMR (300 MHz, MeOD) δ 9.04 (d, J = 8.0 Hz, 1H), 8.40 (d, J = 5.7 Hz, 1H), 8.21 (d, J = 7.7 Hz, 1H), 8.05 (d, J = 11.5 Hz, 1H), 7.67 (s, 1H), 7.42 - 7.03 (m, 5H), 6.81 (s, 2H), 5.63 (d, J = 16.4 Hz, 1H), 5.51 (s, 1H), 5.43 (d, J = 16.5 Hz, 1H), 4.81 (s, 2H), 4.75 - 4.58 (m, 1H), 4.29 - 4.10 (m, 2H), 3.98 - 3.81 (m, 4H), 3.78 - 3.71 (m, 2H), 3.71 - 3.63 (m, 2H), 3.62 - 3.53 (m, 9H), 3.14 - 2.98 (m, 1H), 2.54 (t, J = 6.0 Hz, 2H), 2.08 - 1.93 (m, 2H), 1.03 (t, J = 7.3 Hz, 3H).

[0777] 4.35: (9H-Fluoren-9-yl)methyl (S)-(2-((4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-11-(piperidin-1-ylmethyl)-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)carbamate (compound 4.35) [ka] To a solution of Fmoc-Gly-OH (100.9 mg, 0.34 mmol) in dimethylformamide (550 μL) was added NMM (0.112 mL, 1.02 mmol) and HATU (0.103 g, 0.272 mmol). After stirring the solution at room temperature for 20 minutes, a solution of compound 148 (32.5 mg, 0.068 mmol) in DMF (250 μL) was added, and the reaction mixture was stirred for 16 hours. Purification was carried out as described in General Procedure 9 using a 12 g C18 flash column eluting with a 5 to 40% CH3CN / HO + 0.1% TFA gradient. The resulting residue was repurified as described in General Procedure 9 using a 10 g flash column eluting with a 0 to 10% MeOH / DCM gradient to give the title compound as a yellow powder (15.3 mg, 30% yield).

[0778] LC / MS:C 43 H 40 Calculated m / z for FN5O7 = 757.3, observed [M+H] + =758.6.

[0779] 4.36: (S)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecan-18-amide)-N-(2-(((S)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-11-(piperidin-1-ylmethyl)-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)-3-phenylpropanamide (MT-GGFG-Compound 148) [ka] A 20% solution of piperidine in DMF (2.0 mL) was added to a 50 mL flask containing compound 4.35 (15.3 mg, 0.02 mmol). The solution was stirred at room temperature for 5 minutes and then evaporated to dryness. The resulting residue was then dissolved in 10% DMF / DCM (1.0 mL), followed by the addition of NMM (5.50 μL, 0.05 mmol), compound 4.4 (11.2 mg, 0.02 mmol), and HATU (8.7 mg, 0.02 mmol). The solution was stirred for 45 minutes and then partially evaporated. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 15-45% CHCN / HO + 0.1% TFA gradient, to afford the title product as a yellow powder (7.8 mg, 33% yield).

[0780] LC / MS:C 54 H 62 FN9O 14 Calculated value for m / z=1079.4, observed value [M+H] + =1080.8.

[0781] 1H NMR (300 MHz, MeOD) δ 8.99 (d, J = 8.2 Hz, 1H), 7.52 (d, J = 12.3 Hz, 1H), 7.39 - 7.25 (m, 5H), 7.25 - 7.17 (m, 1H), 6.79 (s, 2H), 5.53 (d, J = 16.4 Hz, 1H), 5.33 (d, J = 16.5 Hz, 1H), 4.80 - 4.72 (m, 1H), 4.32 - 4.11 (m, 2H), 3.98 - 3.79 (m, 6H), 3.76 (t, J = 6.0 Hz, 2H), 3.66 - 3.60 (m, 2H), 3.62 - 3.49 (m, 10H), 3.15 - 3.03 (m, 1H), 2.65 - 2.47 (m, 6H), 1.96 (q, J = 7.4 Hz, 2H), 1.72 - 1.57 (m, 4H), 1.57 - 1.42 (m, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0782] 4.37: tert-Butyl (2-((2-(((S)-1-((2-((4-(N-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)sulfamoyl)phenyl)amino)-2-oxoethyl)amino)-1-oxo-3-phenylpropan-2-yl)amino)-2-oxoethyl)amino)-2-oxoethyl)carbamate (compound 4.37) [ka] The title compound was prepared according to general procedure 7 starting from compound 127 (46 mg). Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 60% CHCN / HO + 0.1% TFA gradient to afford the title compound as a white solid (7.2 mg, 21% yield).

[0783] LC / MS:C 48 H51 N8O 12 Calculated m / z for S = 983.0, observed [M+H] + =983.9.

[0784] 4.38: (S)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecan-18-amide)-N-(2-((4-(N-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)sulfamoyl)phenyl)amino)-2-oxoethyl)-3-phenylpropanamide (MT-GGFG-Compound 127) [ka] The title compound was prepared starting from compound 4.37 (7.2 mg) according to procedure 6 followed by procedure 8. Preparative HPLC purification was performed as described in general procedure 9 eluting with a 10 to 50% CHCN / HO + 0.1% TFA gradient to afford the title compound as a white solid (1 mg, 12% yield).

[0785] LC / MS:C 56 H 60 FN9O 16 Calculated value for m / z=1166.2, observed value [M+H] + =1167.1.

[0786] 4.39: (9H-Fluoren-9-yl)methyl ((7S)-1-((3-azabicyclo[3.1.1]heptan-6-yl)oxy)-7-benzyl-3,6,9,12-tetraoxo-2,5,8,11-tetraazatridecan-13-yl)carbamate (compound 4.39) [ka] To a stirred solution of compound 4.6 (44 mg) in dichloromethane (2 mL) was added 3-azabicyclo[3.1.1]heptan-6-ol (5.3 mg), followed by trifluoroacetic acid (0.4 mL). After 30 minutes, the reaction was concentrated in vacuo. Purification was carried out as described in General Procedure 9 using a 10 g flash column eluted with a 0 to 20% dichloromethane / methanol gradient to afford the title compound as a white solid (14.7 mg, 46% yield).

[0787] LC / MS:C 37 H 42 Calculated m / z for N6O7 = 682.8, observed [M+H] + =683.6.

[0788] 4.40: (2S)-2-(2-(2-aminoacetamido)acetamido)-N-(2-((((3-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-3-azabicyclo[3.1.1]heptan-6-yl)oxy)methyl)amino)-2-oxoethyl)-3-phenylpropanamide (compound 4.40) [ka] The title compound was prepared according to General Procedure 1, starting with compound 1.1 (3 mg, 0.007 mmol) and compound 4.39 (14.7 mg, 0.022 mmol), utilizing 200 μL of DMF. After complete consumption of compound 1.1, a 20% solution of piperidine in DMF (200 μL) was added, and the solution was stirred at room temperature for 10 minutes. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 20-37% CHCN / HO + 0.1% TFA gradient, to afford the title compound as an off-white solid (TFA salt, 1.8 mg, 29% yield).

[0789] LC / MS:C 44 H 49Calculated m / z for FN8O9 = 852.9, observed [M+H] + =853.7.

[0790] 4.41: (2S)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecan-18-amide)-N-(2-((((3-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-3-azabicyclo[3.1.1]heptan-6-yl)oxy)methyl)amino)-2-oxoethyl)-3-phenylpropanamide (MT-GGFG-AM-Compound 117) [ka] The title compound was prepared according to Procedure 8 starting from compound 4.40 (1.8 mg). Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 25 to 45% CHCN / HO + 0.1% TFA gradient to afford the title compound as a white solid (TFA salt, 0.5 mg, 22% yield).

[0791] LC / MS:C 57 H 66 FN9O 15 Calculated value for m / z=1135.5, observed value [M+H] + =1136.3.

[0792] 4.42: (9H-Fluoren-9-yl)methyl (S)-(9-benzyl-1-(3-fluoroazetidin-3-yl)-5,8,11,14-tetraoxo-2-oxa-4,7,10,13-tetraazapentadecan-15-yl)carbamate (compound 4.42) [ka] To a stirred solution of compound 4.6 (144 mg) in dichloromethane (2 mL) was added (3-fluoroazetidin-3-yl)methanol (16 mg), followed by trifluoroacetic acid (0.4 mL). After 30 minutes, the reaction was concentrated in vacuo. Purification was carried out as described in General Procedure 9 using a 10 g flash column eluted with a 0 to 20% dichloromethane / methanol gradient to afford the title compound as a white solid (55 mg, 54% yield).

[0793] LC / MS:C 35 H 39 Calculated m / z for N6FO7 = 674.7, observed [M+H] + =675.6.

[0794] 4.43: (S)-2-(2-(2-aminoacetamido)acetamido)-N-(2-((((1-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-3-fluoroazetidin-3-yl)methoxy)methyl)amino)-2-oxoethyl)-3-phenylpropanamide (compound 4.43) [ka] The title compound was prepared according to General Procedure 1, starting with compound 1.1 (11.6 mg, 0.027 mmol) and compound 4.42 (55 mg, 0.082 mmol), utilizing 500 μL of DMF. After complete consumption of compound 1.1, a 20% solution of piperidine in DMF (500 μL) was added, and the solution was stirred at room temperature for 10 minutes. Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 25-32% CHCN / HO + 0.1% TFA gradient, to afford the title compound as an off-white solid (TFA salt, 8.1 mg, 28% yield).

[0795] LC / MS:C 42 H 46Calculated m / z for F2N8O9 = 844.3, found [M+H] + =845.3.

[0796] 4.44: (S)-2-(1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-12,15-dioxo-3,6,9-trioxa-13,16-diazaoctadecan-18-amide)-N-(2-((((1-(((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)-3-fluoroazetidin-3-yl)methoxy)methyl)amino)-2-oxoethyl)-3-phenylpropanamide (MT-GGFG-AM-Compound 118) [ka] The title compound was prepared according to Procedure 8 starting from compound 4.43 (8.1 mg). Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 25 to 45% CHCN / HO+0.1% TFA gradient to afford the title compound as a white solid (TFA salt, 2.9 mg, 28% yield).

[0797] LC / MS:C 55 H 63 F2N9O 15 Calculated value for m / z=1127.4, observed value [M+H] + =1128.8.

[0798] 4.45: (S)-10-benzyl-23-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-6,9,12,15,18-pentaoxo-3-oxa-5,8,11,14,17-pentaazatricosyl (((S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methyl)carbamate (MC-GGFG-AM-Compound 139) [ka] To compound 4.27 (450 mg) was added a solution of 2,5-dioxopyrrolidin-1-yl 6-(2,5-dioxopyrrol-1-yl)hexanoate (130 mg) and N-ethyldiisopropylamine (250 μL) in DMF (10 mL). The solution was stirred at room temperature for 30 minutes and then concentrated to a volume of approximately 1 mL. Purification was performed as described in General Procedure 9, first using a 60 g C18 flash column eluting with a 10-60% CH3CN / HO + 0.1% TFA gradient, followed by preparative HPLC of impure fractions using a 20-50% CH3CN / HO + 0.1% TFA gradient to afford the title compound as a white solid (320 mg, 66% yield).

[0799] LC / MS:C 51 H 56 FN9O 14 Calculated value for m / z=1037.4, observed value [M+H] + =1038.6.

[0800] 1H NMR (300 MHz, MeOD) δ 8.10 (d, J = 8.1 Hz, 2H), 8.01 (s, 1H), 7.95 (d, J = 7.0 Hz, 1H), 7.74 (d, J = 10.4 Hz, 1H), 7.66 (s, 1H), 7.56 (s, 1H), 7.32 - 7.10 (m, 5H), 6.69 (s, 2H), 5.63 (d, J = 16.4 Hz, 1H), 5.46 (s, 2H), 5.32 (s, 1H), 5.28 (d, J = 16.5 Hz, 1H), 4.88 (s, 2H), 4.67 (d, J = 6.4 Hz, 2H), 4.48 (d, J = 7.1 Hz, 2H), 4.15 (t, J = 4.2 Hz, 2H), 3.92 (dd, J = 17.1, 6.2 Hz, 2H), 3.83 - 3.57 (m, 6H), 3.46 (t, J = 7.1 Hz, 2H), 3.16 (dd, J = 14.0, 5.9 Hz, 1H), 2.95 (dd, J = 13.9, 8.9 Hz, 1H), 2.53 (s, 3H), 2.21 (t, J = 7.6 Hz, 2H), 1.97 - 1.79 (m, 2H), 1.58 (dp, J = 15.0, 7.6 Hz, 4H), 1.29 (dd, J = 16.6, 9.3 Hz, 3H), 1.01 (t, J = 7.3 Hz, 3H).

[0801] 4.46: tert-Butyl (S)-(2-((4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)carbamate (compound 4.46) [ka] A solution of compound 140 (860 mg, 1.7 mmol, TFA salt), Boc-Gly-OH (760 mg, 4.3 mmol), HATU (1.6 g, 4.1 mmol), and N-ethyldiisopropylamine (0.6 mL) in DMF (4 mL) was stirred at room temperature for 24 hours and then poured into water (50 mL). The resulting solid was collected by filtration, redissolved in 10% MeOH / DCM, and purified as described in General Procedure 9 using a 30 g silica column eluted with 0 to 10% MeOH / DCM to give the title compound as a yellow solid (750 mg, 80% yield).

[0802] LC / MS:C 27 H 27 Calculated m / z for FN4O7 = 538.5, observed [M+H] + =539.4.

[0803] 1 H NMR (300 MHz, MeOD) δ 8.84 (d, J = 8.4 Hz, 1H), 8.52 (s, 1H), 8.00 (s, 1H), 7.87 (d, J = 12.1 Hz, 1H), 7.62 (s, 1H), 5.60 (d, J = 16.3 Hz, 1H), 5.40 (d, J = 16.4 Hz, 1H), 5.27 (s, 2H), 4.02 (s, 2H), 1.99 (dt, J = 8.7, 6.7 Hz, 2H), 1.52 (s, 9H), 1.03 (t, J = 7.4 Hz, 3H).

[0804] 4.47: (S)-1-((2-(((S)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)amino)-1-oxo-3-phenylpropan-2-aminium (compound 4.47) [ka] The title compound was prepared in three steps from compound 4.46 (750 mg). The Boc protecting group was cleaved in neat TFA (2 mL) followed by precipitation in EtO (50 mL). The solid was collected by filtration and added to a solution of 2,5-dioxopyrrolidin-1-yl(2S)-2-[(tert-butoxycarbonyl)amino]-3-phenylpropanoate (340 mg, 1.1 equiv.) and N-ethyldiisopropylamine (300 μL) in DMF (1.7 mL). The solution was stirred at room temperature for 30 minutes and then pipetted into EtO (50 mL). The precipitate was collected by filtration, dried under reduced pressure, and then dissolved in neat TFA (2 mL). After 20 minutes, EtO (50 mL) was added, and the precipitate was collected by filtration to give the title compound as a yellow solid (531 mg, 54% yield).

[0805] LC / MS:C 31 H 28 Calculated m / z for FN5O6 = 585.2, found [M+H] + =586.1.

[0806] 4.48: 2-((2-(((S)-1-((2-(((S)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)amino)-1-oxo-3-phenylpropan-2-yl)amino)-2-oxoethyl)amino)-2-oxoethane-1-aminium (compound 4.48) [ka] To compound 4.47 (490 mg) was added a solution of Boc-gly-gly-NHS (250 mg, 1.1 equivalents) and N-ethyldiisopropylamine (250 μL) in DMF (3 mL). The solution was stirred at room temperature for 30 minutes and then pipetted into EtO (50 mL). The precipitate was collected by filtration and then dissolved in neat TFA (2 mL). After 20 minutes, EtO (50 mL) was added and the precipitate was collected by filtration to give the title compound as a yellow solid (500 mg, 88% yield).

[0807] LC / MS:C 35 H 34 Calculated m / z for FN7O8 = 699.2, observed [M+H] + =700.4.

[0808] 4.49: 6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-N-(2-((2-(((S)-1-((2-(((S)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)amino)-1-oxo-3-phenylpropan-2-yl)amino)-2-oxoethyl)amino)-2-oxoethyl)hexanamide (MC-GGFG-Compound 140) [ka] To compound 4.48 (500 mg) was added a solution of 2,5-dioxocyclopentyl 6-(2,5-dioxopyrrol-1-yl)hexanoate (210 mg, 1.1 equiv.) and N-ethyldiisopropylamine (215 μL) in DMF (4 mL). The solution was stirred at room temperature for 30 minutes and then pipetted into EtO (50 mL). The precipitate was collected by filtration and dissolved in DMF (2 mL). Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 24-38% CHCN / HO + 0.1% TFA gradient, to afford the title compound as a yellow solid (190 mg, 40% yield).

[0809] LC / MS:C 45 H 45 FN8O 11 Calculated m / z = 892.9, measured value [M+H] + =893.6.

[0810] 1 H NMR (300 MHz, CD3CN) δ 8.67 (d, J = 8.4 Hz, 1H), 8.44 (s, 1H), 7.78 (d, J = 12.1 Hz, 1H), 7.41 (s, 1H), 7.30 (d, J = 4.3 Hz, 4H), 7.26 - 7.16 (m, 1H), 6.72 (s, 2H), 5.52 (d, J = 16.4 Hz, 1H), 5.31 (d, J = 16.4 Hz, 1H), 5.12 (s, 2H), 4.64 (dd, J = 9.7, 5.0 Hz, 1H), 4.11 (d, J = 3.2 Hz, 2H), 3.87 - 3.68 (m, 4H), 3.37 (t, J = 7.1 Hz, 2H), 3.00 (dd, J = 14.0, 9.7 Hz, 1H), 2.20 (t, J = 7.6 Hz, 2H), 1.49 (dq, J = 19.5, 7.4 Hz, 4H), 1.22 (p, J = 7.6, 7.1 Hz, 2H), 0.94 (t, J = 7.3 Hz, 3H).

[0811] 4.50: tert-Butyl (S)-(2-((4-ethyl-8-fluoro-4-hydroxy-11-(hydroxymethyl)-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)carbamate (compound 4.50) [ka] A solution of compound 4.46 (1.8 g), iron(II) sulfate heptahydrate (1.4 g, 1.5 equiv.), and sulfuric acid (450 μL, 2.5 equiv.) in MeOH (33 mL) was heated to 60° C., and hydrogen peroxide (1.25 mL, 12 equiv.) was added dropwise over 10 minutes. The solution was heated for an additional 20 minutes, then cooled to room temperature and poured into ice water (approximately 200 mL). The brown precipitate was collected by filtration, and the filtrate was quenched with saturated aqueous NaSO. The MeOH was evaporated, and the solution was allowed to stand for 2 hours, during which time a second brown precipitate formed. This precipitate was collected by filtration, and the combined precipitates were purified as described in General Procedure 9 using a 50 g silica column eluting with a 0 to 15% MeOH / DCM gradient to afford the title compound as a yellow solid (860 mg, 45% yield).

[0812] LC / MS:C 28 H 29 Calculated m / z for FN4O8 = 568.5, observed [M+H] + =569.7.

[0813] 4.51: (S)-1-((2-(((S)-4-ethyl-8-fluoro-4-hydroxy-11-(hydroxymethyl)-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)amino)-1-oxo-3-phenylpropan-2-aminium (compound 4.51) [ka] The title compound was prepared in three steps from compound 4.50 (750 mg). The Boc protecting group was cleaved in neat TFA (2 mL) followed by precipitation in EtO (100 mL). The solid was collected by filtration and added to a solution of 2,5-dioxopyrrolidin-1-yl(2S)-2-[(tert-butoxycarbonyl)amino]-3-phenylpropanoate (600 mg, 1.1 equiv.) and N-ethyldiisopropylamine (300 μL) in DMF (7 mL). The solution was stirred at room temperature for 30 minutes and then pipetted into EtO (100 mL). The precipitate was collected by filtration, dried under reduced pressure, and then dissolved in neat TFA (2 mL). After 20 min, Et2O (100 mL) was added and the precipitate was collected by filtration to give the title compound as a yellow solid (756 mg, 78% yield).

[0814] LC / MS:C 32 H 30 Calculated m / z for FN5O7 = 615.2, found [M+H] + =616.3.

[0815] 4.52: 2-((2-(((S)-1-((2-(((S)-4-ethyl-8-fluoro-4-hydroxy-11-(hydroxymethyl)-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)amino)-1-oxo-3-phenylpropan-2-yl)amino)-2-oxoethyl)amino)-2-oxoethan-1-aminium (compound 4.52) [ka] To compound 4.51 (756 mg) was added a solution of Boc-gly-gly-NHS (375 mg, 1.1 equivalents) and N-ethyldiisopropylamine (400 μL) in DMF (5 mL). The solution was stirred at room temperature for 30 minutes and then pipetted into EtO (75 mL). The precipitate was collected by filtration and then dissolved in neat TFA (4 mL). After 20 minutes, EtO (100 mL) was added and the precipitate was collected by filtration to give the title compound as a yellow solid (826 mg, 95% yield).

[0816] LC / MS:C 36 H 36 Calculated m / z for FN7O9 = 729.2, found [M+H] + =730.2.

[0817] 4.53: 6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-N-(2-((2-(((S)-1-((2-(((S)-4-ethyl-8-fluoro-4-hydroxy-11-(hydroxymethyl)-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-2-oxoethyl)amino)-1-oxo-3-phenylpropan-2-yl)amino)-2-oxoethyl)amino)-2-oxoethyl)hexanamide (MC-GGFG-Compound 141) [ka] To compound 4.52 (826 mg) was added a solution of 2,5-dioxocyclopentyl 6-(2,5-dioxopyrrol-1-yl)hexanoate (382 mg, 1.1 equiv.) and N-ethyldiisopropylamine (300 μL) in DMF (5.5 mL). The solution was stirred at room temperature for 30 minutes and then pipetted into EtO (100 mL). The precipitate was collected by filtration and dissolved in DMF (2 mL). Preparative HPLC purification was performed as described in General Procedure 9, eluting with a 25-40% CHCN / HO + 0.1% TFA gradient, to afford the title compound as a yellow solid (370 mg, 35% yield).

[0818] LC / MS:C 46 H 47 FN8O 12 Calculated value for m / z=922.9, observed value [M+H] + =923.8.

[0819] 1 H NMR (300 MHz, CD3CN) δ 8.63 (d, J = 8.4 Hz, 1H), 7.67 (d, J = 11.9 Hz, 1H), 7.38 - 7.27 (m, 5H), 7.24 (d, J = 4.3 Hz, 1H), 6.72 (s, 2H), 5.48 (d, J = 16.4 Hz, 1H), 5.28 (d, J = 16.3 Hz, 1H), 5.24 - 5.01 (m, 4H), 4.65 (dd, J = 9.7, 4.9 Hz, 1H), 4.13 (s, 2H), 3.85 - 3.75 (m, 3H), 3.37 (t, J = 7.1 Hz, 2H), 3.00 (dd, J = 14.0, 9.8 Hz, 1H), 2.21 (t, J = 7.6 Hz, 2H), 1.51 (dp, J = 22.0, 7.4 Hz, 4H), 1.22 (p, J = 7.4, 7.0 Hz, 2H), 0.94 (t, J = 7.3 Hz, 3H).

[0820] 4.54: tert-Butyl ((S)-1-(((S)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-1-oxopropan-2-yl)carbamate (compound 4.54) [ka] Compound 3.4 (500 mg, 1.0 mmol) was added with TFA (4 mL). The solution was left at room temperature for 1 hour, then EtO (100 mL) was added, and the precipitate was collected by filtration. The solid was dissolved in DMF (3.4 mL), and Boc-Ala-OH (590 mg, 3.1 mmol, 3 equiv.) and HATU (1.2 g, 3.1 mmol, 3 equiv.) were added, followed by N-ethyldiisopropylamine (0.9 mL, 5.2 mmol, 5 equiv.). The solution was stirred at room temperature for 3 days, then poured into ice water (50 mL), and the precipitate was collected by filtration to give the title compound as a brown solid (125 mg, 22% yield).

[0821] LC / MS:C 28 H 29 Calculated m / z for FN4O7 = 552.6, observed [M+H] + =553.7.

[0822] 4.55: (S)-2-amino-N-((S)-1-(((S)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-1-oxopropan-2-yl)-3-methylbutanamide (compound 4.55) [ka] To compound 4.54 (125 mg, 0.225 mmol) in a 100 mL round-bottom flask was added TFA (2 mL). After the solution was allowed to stand for 10 minutes, EtO (50 mL) was added, and the precipitate was collected by filtration. The resulting orange solid was added to a solution of Boc-Val-NHS (78 mg, 0.25 mmol, 1.1 equiv.) and N-ethyldiisopropylamine (80 μL, 0.45 mmol, 2 equiv.) in DMF (2 mL). After stirring at room temperature for 30 minutes, the solution was pipetted into EtO (40 mL) in a 50 mL Falcon tube, and the precipitate was collected by centrifugation and decanting the EtO. The pellet was dissolved in TFA (2 mL) and allowed to stand for 10 minutes, after which EtO (40 mL) was added. The precipitate was collected by centrifugation and decanting the EtO. The pellet was dried under high vacuum to give the title compound as an orange solid (135 mg, 90% yield over three steps).

[0823] LC / MS:C 28 H 30 Calculated m / z for FN5O6 = 551.2, found [M+H] + =552.2.

[0824] 4.56: 6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-N-((S)-1-(((S)-1-(((S)-4-ethyl-8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl)amino)-1-oxopropan-2-yl)amino)-3-methyl-1-oxobutan-2-yl)hexanamide (MC-VA-Compound 140) [ka] To compound 4.55 (20 mg, 0.03 mmol) was added a solution of 2,5-dioxopyrrolidin-1-yl 6-(2,5-dioxopyrrol-1-yl)hexanoate (11 mg, 0.036 mmol) and N-ethyldiisopropylamine (10 μL) in DMF (1 mL). The solution was stirred at room temperature for 30 minutes and then directl...

Claims

1. A compound having the formula (I): 【Chemical 1】 wherein, is selected from R １ is selected from -CH ３ , -CHF ２ , -CF ３ , -F, -Br, -Cl, -OCH ３ , -OCF ３ and -NH ２ and R ２ is selected from -CH ３ , -CF ３ , -F, -Br, -Cl, -OCH ３ and -OCF ３ and is selected from R １ is -NH ２ In the case where, R is R ３ or R ４ and when R is １ is -NH ２ otherwise, R is R ４ and R ３ is -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -(C １ ~C ６ alkyl)-O-R ５ , [Chemical Formula 2] -CO ２ R ８ , -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl, and is selected from R ４ is [Chemical Formula 3] is selected from R ５ is selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl R ６ and R ７ each independently represents -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -(C １ ~C ６ alkyl)-O-R ５ , -C ３ ~C ８ heterocycloalkyl and -C(O)R １７ and is selected from R ８ is selected from -H, -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, and -C ３ to -C ８ heterocycloalkyl, Each R ９ is independently selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl, Each R １０ is independently selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -NR １４ R １４’ , -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, Each R １０’ is independently selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl R １１ is selected from -H and -C １ ~C ６ alkyl, R １２ is -H, -C １ ~C ６ alkyl, -CO ２ R ８ , -aryl, -heteroaryl, -(C １ ~C ６ alkyl)-aryl, -S(O) ２ R １６ and 【Chemical 4】 alkyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl groups may each be optionally substituted, R １３ is selected from -H and -C １ ~C ６ alkyl, R １４ and R １４’ are each independently selected from -H, C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, and -C ３ ~C ８ heterocycloalkyl, R １６ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -aryl, -heteroaryl, and -(C １ to -C ６ alkyl)-aryl, R １７ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -C ３ to -C ８ heterocycloalkyl, -(C １ to -C ６ alkyl)-C ３ to -C ８ heterocycloalkyl, -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, R １８ and R １９ together with the N atom to which they are attached, form a 4-, 5-, 6- or 7-membered ring having from 0 to 3 substituents selected from halogen, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl and -(C １ ~C ６ alkyl)-O-R ５ and form a 4-, 5-, 6- or 7-membered ring having from 0 to 3 substituents selected from halogen, -C R ２４ , R ２５ and R ２６ are each -C １ ~C ６ alkyl, X ａ and X ｂ are each independently selected from NH, O, and S, X ｃ is selected from O, S and S(O) ２ and the compound or a pharmaceutically acceptable salt or protected form thereof.

2. The compound according to claim 1, or a pharmaceutically acceptable salt or protected form thereof, selected from R ４ is ​

3. A compound having the formula (II): wherein, [Chemical Formula 6] is selected from is selected from R ２ is selected from -CH ３ , -CF ３ , -F, -Br, -Cl, -OCH ３ and -OCF ３ and is selected from R ２０ is -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -(C １ ~C ６ alkyl)-O-R ５ , [Chemical 7] -CO ２ R ８ , -aryl, -heteroaryl, -(C １ ~C ６ alkyl)-aryl, [Chemical Formula 8] the compound according to claim 1, or a pharmaceutically acceptable salt or protected form thereof. R ５ is selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl, R ６ and R ７ are each independently, -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -(C １ ~C ６ alkyl)-O-R ５ , -C ３ ~C ８ heterocycloalkyl and -C(O)R １７ selected from, R ８ is selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, and -C ３ ~C ８ heterocycloalkyl, Each R ９ is independently selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl, Each R １０ is independently selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -NR １４ R １４’ , -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, Each R １０’ is independently selected from -H, -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, R １１ is selected from -H and -C １ ~C ６ alkyl, R １２ is -H, -C １ ~C ６ alkyl, -CO ２ R ８ , -aryl, -heteroaryl, -(C １ ~C ６ alkyl)-aryl, -S(O) ２ R １６ and 【Chemical Formula 9】

4. R １３ is selected from -H and -C １ ~C ６ alkyl, R １４ and R １４’ are each independently selected from -H, C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, and -C ３ ~C ８ heterocycloalkyl, R １６ is selected from -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl, and -(C １ ~C ６ alkyl)-aryl, R １７ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -C ３ to -C ８ heterocycloalkyl, -(C １ to -C ６ alkyl)-C ３ to -C ８ heterocycloalkyl, -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, R １８ and R １９ together with the N atom to which they are attached form a 4-, 5-, 6-, or 7-membered ring having from 0 to 3 substituents selected from halogen, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl and -(C １ ~C ６ alkyl)-O-R ５ and form a 4-, 5-, 6-, or 7-membered ring having from 0 to 3 substituents selected from the group consisting of halogen, -C R ２４ 、R ２５ and R ２６ are each -C １ ~C ６ alkyl, X ａ and X ｂ are each independently selected from NH, O, and S, X ｃ is selected from O, S, and S(O) ２ ​

5. or; R ２ is -CH ３ , -CF ３ , -F, -Cl, -OCH ３ and -OCF ３ selected from, a compound according to claim 3 or a pharmaceutically acceptable salt or protected form thereof. or; R ２０ is (a) -H, -C １ ~C ６ alkyl, -(C １ ~C ６ alkyl)-O-R ５ , 【Chemical Formula 10】 -(C １ ~C ６ alkyl)-aryl, 【Chemical 11】 The compound according to claim 3, or a pharmaceutically acceptable salt or protected form thereof, selected from (b) -H, -C １ ~C ６ alkyl, -(C １ ~C ６ alkyl)-O-R ５ , 【Chemical Formula 12】 -(C １ ~C ６ alkyl)-aryl, 【Chemical 13】

6. (c)-H, -C １ ~C ６ alkyl, -(C １ ~C ６ alkyl)-O-R ５ , 【Chemical Formula 14】 A compound having the formula (IIa):

7. The compound according to claim 6, or a pharmaceutically acceptable salt or protected form thereof, selected from 【Chemical Formula 15】 having, wherein R ２０ R ５ R ６ R ７ R ８ R ９ R １０ R １０’ R １１ R １２ R １３ R １４ R １４’ R １６ R １７ R １８ R １９ R ２４ R ２５ R ２６ X ａ X ｂ and X ｃ are as defined in claim 3, a compound according to claim 3 or a pharmaceutically acceptable salt or protected form thereof.

8. R ２０ is -H, -C １ ~C ６ alkyl, -(C １ ~C ６ alkyl)-O-R ５ , 【Chemical Formula 16】 A compound having the formula (III): wherein, is selected from 【Chemical 17】 is selected from the compound according to claim 1, or a pharmaceutically acceptable salt or protected form thereof. R ２ is selected from -CH ３ , -CF ３ , -F, -Br, -Cl, -OCH ３ and -OCF ３ and is selected from R １５ is selected from -CH ３ , -CF ３ , -F, -Br, -Cl, -OCH ３ and -OCF ３ and is selected from R ４ is 【Chemical Formula 18】

9. R ５ is selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl, R ８ is selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, and -C ３ ~C ８ heterocycloalkyl, Each R ９ is independently selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl, Each R １０ is independently, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -NR １４ R １４’ , -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl, and is selected from Each R １０’ is independently selected from -H, -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, R １１ is selected from -H and -C １ ~C ６ alkyl, R １２ is -H, -C １ ~C ６ alkyl, -CO ２ R ８ , -aryl, -heteroaryl, -(C １ ~C ６ alkyl)-aryl, -S(O) ２ R １６ and 【Chemical Formula 19】 selected from R １３ is selected from -H and -C １ ~C ６ alkyl, R １４ and R １４’ each independently represents -H, C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, and -C ３ ~C ８ is selected from heterocycloalkyl, R １６ is selected from -C １ -C ６ alkyl, -C ３ -C ８ cycloalkyl, -aryl, -heteroaryl, and -(C １ -C ６ alkyl)-aryl, R １８ and R １９ together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered ring having from 0 to 3 substituents selected from halogen, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl and -(C １ ~C ６ alkyl)-O-R ５ and form a 4-, 5-, 6- or 7-membered ring having from 0 to 3 substituents selected from the group consisting of halogen, -C R ２４ , R ２５ and R ２６ are each -C １ ~C ６ alkyl, X ａ and X ｂ are each independently selected from NH, O, and S, X ｃ is selected from O, S, and S(O) ２ and the compound according to claim 8, or a pharmaceutically acceptable salt or protected form thereof.

10. (a) R ２ is selected from -F, -Br and -Cl, and / or (b) R １５ is -CH ３ , -CF ３ , -OCH ３ and -OCF ３ selected from and / or (c) R ４ is 【Chemical 20】

11. A compound having the formula (IIIa) or (IIIb):

12. R １５ is -CH ３ or -OCH ３ and is the compound according to claim 8 or a pharmaceutically acceptable salt or protected form thereof. The compound according to claim 11, or a pharmaceutically acceptable salt or protected form thereof, selected from

13. 【Chemical Formula 21】 having, wherein R ４ R ５ R ８ R ９ R １０ R １０’ R １１ R １２ R １３ R １４ R １４’ R １６ R １８ R １９ R ２４ R ２５ R ２６ X ａ X ｂ and X ｃ is as defined in claim 8, a compound according to claim 8 or a pharmaceutically acceptable salt or protected form thereof. alkyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl groups are each R ４ is 【Chemical 22】 (a) halogen, acyl, acyloxy, alkoxy, carboxy, hydroxy, amino, amide, nitro, cyano, azide, alkylthio, thio, sulfonyl, sulfonamide, alkyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl, or The compound according to any one of claims 1 to 12, or a pharmaceutically acceptable salt or protected form thereof, which may be substituted with one or more substituents selected from (b) halogen, acyl, acyloxy, alkoxy, carboxy, hydroxy, amino, amide, nitro, cyano, azide, alkylthio, thio, sulfonyl and sulfonamide

14. The compound according to claim 1, or a pharmaceutically acceptable salt or protected form thereof, wherein the compound is selected from compounds 100 to 168 described in Table 1.

15. A complex having the formula (X): (X) wherein, ​ T - [L - (D) ｍ ｎ ​ ​ ​ T is the targeting moiety, L is the linker, D is the compound according to claim 1, m is an integer between 1 and 4, n is an integer between 1 and 10, Complex.

16. Formula (X): T - [L - (D) ｍ ｎ ​ (X) A complex having, wherein, T is the targeting moiety, L is the linker, m is an integer between 1 and 4, n is an integer between 1 and 10, D is a compound of formula (IV): 【Chemical 23】 wherein, R １ａ is selected from -CH ３ , -CF ３ , -F, -Br, -Cl, -OCH ３ , -OCF ３ and -NH ２ and is selected from R ２ａ is selected from -CH ３ , -CF ３ , -F, -Br, -Cl, -OCH ３ and -OCF ３ and is selected from X is -O-, -S- or -NH-, and R ４ａ is 【Chemical formula 24】 selected from, * is the point of attachment to X, p is 1, 2, 3 or 4, or X is O, and R ４ａ -X- is 【Chemical 25】 selected from, R ５ａ is selected from -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl, and -(C １ ~C ６ alkyl)-aryl, R ８ａ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, and -C ３ to -C ８ heterocycloalkyl, Each R ９ａ is independently selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, or R ９ａ is absent and X ｂ = X Each R １０ａ independently represents -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -aryl, -heteroaryl, -(C １ to -C ６ alkyl)-aryl and 【Chemical 26】 selected from, Each R １０ａ’ is independently selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl Each R １０ｂ is independently selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, R １１ａ is absent or is -C １ ~C ６ alkyl, R １２ａ is -C １ ~C ６ alkyl, -CO ２ R ８ａ , -aryl, -heteroaryl, -(C １ ~C ６ alkyl)-aryl, -S(O) ２ R １６ａ and 【Chemical 27】 selected from, R １３ａ is selected from -H and -C １ ~C ６ alkyl, R １４ａ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, and -C ３ to -C ８ heterocycloalkyl, R １４ａ’ is selected from H, -C １ to C ６ alkyl, -C ３ to C ８ cycloalkyl, and -C ３ to C ８ heterocycloalkyl, R １６ａ is selected from -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl, and -(C １ ~C ６ alkyl)-aryl R ２１ is selected from -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl and -(C １ ~C ６ alkyl)-O-R ５ａ and is selected from R ２２ and R ２３ are each independently, -H, -halogen, C １ ~C ６ alkyl, and -C ３ ~C ８ selected from cycloalkyl, R ２４ , R ２５ and R ２６ are each -C １ ~C ６ alkyl, X ａ and X ｂ are each independently selected from NH, O, and S, X ｃ is selected from O, S, and S(O) ２ and 【Chemical Formula 28】 represents the point of attachment to the linker L, the alkyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl groups may each be substituted, Complex.

17. R １ａ is (a) -CH ３ , -CF ３ , -OCH ３ , -OCF ３ and -NH ２ ; or (b) -CH ３ , -OCH ３ and NH ２ The complex according to claim 16, selected from.

18. (a) R ２ａ is selected from -F, -Br and -Cl, and / or (b) X is -O-, -S- or -NH-, and R ４ａ is 【Chemical formula 29】 selected from, The complex according to claim 16.

19. Formula (X): T - [L - (D) ｍ ｎ ​ (X) A complex having, wherein, T is the targeting moiety, L is the linker, m is an integer between 1 and 4, n is an integer between 1 and 10, D is a compound of formula (V): 【Chemical Formula 30】 wherein, R ２ａ is selected from -CH ３ , -CF ３ , -F, -Br, -Cl, -OCH ３ and -OCF ３ and is selected from R ２０ａ is -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -(C １ ~C ６ alkyl)-O-R ５ , 【Chemical 31】 -CO ２ R ８ , -aryl, -heteroaryl, -(C １ ~C ６ alkyl)-aryl, 【Chemical 32】 selected from, R ５ is selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl, R ６ and R ７ are each independently, -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -(C １ ~C ６ alkyl)-O-R ５ , -C ３ ~C ８ heterocycloalkyl and -C(O)R １７ selected from, R ８ is selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, and -C ３ ~C ８ heterocycloalkyl, Each R ９ is independently selected from -H, -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, Each R １０ is independently, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl, -(C １ ~C ６ alkyl)-aryl and 【Chemical 33】 selected from, R10' is -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl, and is selected from R １１ is selected from -H and -C １ ~C ６ alkyl, R １２ is -H, -C １ ~C ６ alkyl, -CO ２ R ８ , -aryl, -heteroaryl, -(C １ ~C ６ alkyl)-aryl, -S(O) ２ R １６ and 【Chemical 34】 selected from, R １３ is selected from -H and -C １ ~C ６ alkyl, R １４ and R １４’ each independently represents -H, C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, and -C ３ ~C ８ is selected from heterocycloalkyl, R １６ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -aryl, -heteroaryl, and -(C １ to -C ６ alkyl)-aryl R １７ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -C ３ to -C ８ heterocycloalkyl, -(C １ to -C ６ alkyl)-C ３ to -C ８ heterocycloalkyl, -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, R １８ and R １９ together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered ring having from 0 to 3 substituents selected from halogen, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl and -(C １ ~C ６ alkyl)-O-R ５ and form a 4-, 5-, 6- or 7-membered ring having from 0 to 3 substituents selected from the group consisting of halogen, -C R ２４ , R ２５ and R ２６ are each -C １ ~C ６ alkyl, X ａ and X ｂ are each independently selected from NH, O, and S, X ｃ is selected from O, S, and S(O) ２ and 【Chemical Formula 35】 represents the point of attachment to the linker L, the alkyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl groups may each be substituted, Complex.

20. (a) R ２ａ is F, and / or (b) R ２０ａ is -H, -C １ ~C ６ alkyl, -(C １ ~C ６ alkyl)-O-R ５ , 【Chemical 36】 -(C １ ~C ６ alkyl)-aryl, 【Chemical 37】 selected from, The complex according to claim 19.

21. Formula (X): T - [L - (D) ｍ ｎ ​ (X) A complex having, wherein, T is the targeting moiety, L is the linker, m is an integer between 1 and 4, n is an integer between 1 and 10, D is a compound of formula (VI): 【Chemical Formula 38】 wherein, R ２ａ is selected from -CH ３ , -CF ３ , -F, -Br, -Cl, -OCH ３ and -OCF ３ and is selected from X is -O-, -S- or -NH-, and R ２５ is -C １ ~C ６ alkyl, -(C １ ~C ６ alkyl)-O-R ５ａ , -CO ２ R ８ａ , -C(O)-, -aryl, -heteroaryl, -(C １ ~C ６ alkyl)-aryl, 【Chemical 39】 selected from, * is the point of attachment to X, p is 1, 2, 3 or 4, or X is O, and R ２５ -X- is 【Chemical Formula 40】 selected from, R ５ａ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -aryl, -heteroaryl, and -(C １ to -C ６ alkyl)-aryl, R ６ａ is selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, and -C ３ ~C ８ heterocycloalkyl, R ７ａ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -(C １ to -C ６ alkyl)-O-R ５ａ and -C ３ to -C ８ heterocycloalkyl and -C(O)R １７ａ and is selected from R ８ａ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, and -C ３ to -C ８ heterocycloalkyl, Each R ９ａ is independently selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, or R ９ａ is absent and X ｂ = X Each R １０ａ is independently, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl, -(C １ ~C ６ alkyl)-aryl and 【Chemical 41】 selected from, Each R １０ａ’ is independently selected from -H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ ~C ６ alkyl)-aryl, Each R １０ｂ is independently selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, R １１ａ is absent or is -C １ ~C ６ alkyl, R １２ａ is -C １ ~C ６ alkyl, -CO ２ R ８ａ , -aryl, -heteroaryl, -(C １ ~C ６ alkyl)-aryl, -S(O) ２ R １６ａ and 【Chemical 42】 selected from, R １３ａ is selected from -H and -C １ ~C ６ alkyl, R １４ａ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, and -C ３ to -C ８ heterocycloalkyl, R １４ａ’ is selected from H, -C １ ~C ６ alkyl, -C ３ ~C ８ cycloalkyl, and -C ３ ~C ８ heterocycloalkyl, R １６ａ is selected from -C １ -C ６ alkyl, -C ３ -C ８ cycloalkyl, -aryl, -heteroaryl, and -(C １ -C ６ alkyl)-aryl, R １７ａ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl, -C ３ to -C ８ heterocycloalkyl, -(C １ to -C ６ alkyl)-C ３ to -C ８ heterocycloalkyl, -aryl, -heteroaryl and -(C １ to -C ６ alkyl)-aryl, R ２１ is selected from -C １ to -C ６ alkyl, -C ３ to -C ８ cycloalkyl and -(C １ to -C ６ alkyl)-O-R ５ａ and is selected from R ２２ and R ２３ are each independently selected from -H, -halogen, C １ ~C ６ alkyl, and -C ３ ~C ８ cycloalkyl, R ２４ , R ２５ａ and R ２６ are each -C １ ~C ６ alkyl, X ａ and X ｂ are each independently selected from NH, O, and S, X ｃ is selected from O, S, and S(O) ２ and 【Chemical 43】 represents the point of attachment to the linker L, the alkyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl groups may each be substituted, Complex.

22. (a) R ２ａ is F, and / or (b) X is -O-, -S- or -NH-, and R ２５ is -C １ ~ C ６ alkyl, -(C １ ~ C ６ alkyl)-O-R ５ａ -(C １ ~ C ６ alkyl)-aryl, 【Chemical Formula 44】 selected from or (c) X is O, and R ２５ -X- is 【Chemical 45】 selected from, The complex according to claim 21.

23. X is -O-, -S- or -NH-, and R ２５ is -C １ ~C ６ alkyl, -(C １ ~C ６ alkyl)-O-R ５ａ ,-(C １ ~C ６ alkyl)-aryl, 【Chemical 46】 The complex according to claim 21, selected from.

24. The alkyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl groups are each, (a) halogen, acyl, acyloxy, alkoxy, carboxy, hydroxy, amino, amide, nitro, cyano, azide, alkylthio, thio, sulfonyl, sulfonamide, alkyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl, or (b) halogen, acyl, acyloxy, alkoxy, carboxy, hydroxy, amino, amide, nitro, cyano, azide, alkylthio, thio, sulfonyl and sulfonamide The complex according to any one of claims 16 to 23, which may be substituted with one or more substituents selected from [

25. ] (a) m is 1 or 2, and / or (b) n is between 2 and 8, The complex according to any one of claims 15 to 23. [

26. ] The complex according to any one of claims 15 to 23, wherein L is a cleavable linker or a protease-cleavable linker. [

27. ] The complex according to claim 26, wherein L comprises a dipeptide, a tripeptide or a tetrapeptide. [

28. ] (a) T binds to a tumor-associated antigen, and / or (b) T is an antibody or an antigen-binding antibody fragment, and / or (c) T is a bispecific antibody or a multispecific antibody, The complex according to any one of claims 15 to 23. [

29. ] A pharmaceutical composition comprising a compound according to any one of claims 1 to 12 and 14 or a pharmaceutically acceptable salt or protected form thereof, or a complex according to any one of claims 15 to 23, and a pharmaceutically acceptable carrier or diluent. [

30. ] A medicament for the treatment of cancer, an autoimmune disease or a viral infection, comprising a compound according to any one of claims 1 to 12 and 14 or a pharmaceutically acceptable salt or protected form thereof, or a complex according to any one of claims 15 to 23.

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