Bicyclo[1.1.1]pentane based topoisomerase inhibitors and methods of their use

Abstract

Disclosed herein are topoisomerase inhibitors, compositions comprising them, and methods of their use to treat cancer. Particular compounds are of the formula (I) and pharmaceutically acceptable salts thereof, the substituents of which are defined herein.

Description

[0001] TSRI 2255.1PC / CIB0907P 18350.026WO1

[0002] BICYCLO[1.1.1]PENTANE BASED TOPOISOMERASE INHIBITORS AND METHODS OF THEIR USE

[0003] CROSS-REFERENCE TO RELATED APPLICATIONS

[0004] This application claims priority to U.S. provisional patent application no. 63 / 690,346 filed September 4, 2024, the entirety of which is incorporated herein by reference.

[0005] 1. BACKGROUND

[0006] During DNA replication helicases unwind double-stranded DNA (dsDNA) imparting tension on the helical flanks of the replication bubble. To off-set tension, DNA supercoils by forming a twist in the entire tertiary structure. This positive supercoiling regulates DNA metabolism, storage, replication, and transcription. When tension in dsDNA exceeds a capacity that facilitates each of these biological processes, i.e. DNA negative supercoiling, the tension must be released. Topoisomerases are a class of nuclear localized enzymes that bind to and interconvert DNA between supercoiled and relaxed states to relieve or moderate tension. The human genome encodes six topoisomerases, TOPI, TOP1MT, TOP2a, TOP2P, TOP3a and TOP3P, that all remove DNA negative supercoiling each with unique specificities and mechanisms of action. One example, Topoisomerase 1 (TOPI), binds directly to DNA, creates a single-stranded DNA nick, and interconverts the DNA to unwind and alleviate tension. Failure of the cell to unwind negatively supercoiled DNA can lead to tension-induced dsDNA breaks and ensuing cell death. Topoisomerase 1 is a highly conserved enzyme in both prokaryotic and eukaryotic cells, and in each organism serves an essential cellular function.

[0007] Camptothecin is a natural product derived alkaloid discovered in 1966 as an inhibitor of TOPI. Derivatization of Camptothecin has led to the discovery of several improved analogues that have shown clinical success as chemotherapy agents including topotecan, irinotecan, belotecan, and deruxtecan (DXd). In addition to their use as stand-alone chemotherapy agents, TOPI inhibitors are commonly used as payloads for antibody-drug conjugates (ADCs) to improve clinical efficacy and tolerability. Tumortargeting of TOPI inhibitors by antibodies addresses many of the limitations imposed by the stand-alone agents including off-target toxicity in rapidly dividing bone-marrow cells (i.e., neutropenia), and poor pharmacokinetic parameters due to rapid blood clearance. The drug-to-antibody ratio (DAR) of ADCs is commonly 2-8. Trastuzumab deruxtecan is an ADC containing deraxtecan as the payload with DAR of 8. It was recently approved to treat breast cancer or gastric or gastroesophageal adenocarcinoma. Still a large percentage of the patients treated with the drug have no response. There is a need for additional novel TOP 1 inhibitors with enhanced potency, tumor penetration, and reduced efflux to be incorporated into ADC as the payloads with potentially reduced DAR to improve the pharmacokinetics and tolerability. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0008] 2. SUMMARY

[0009] This invention is directed to novel, potent topoisomerase inhibitors, methods of their preparation, antibody-drug-conjugates (ADCs) comprising them, compositions comprising them, and methods of their use. In particular, this invention encompasses topoisomerase inhibitors of the formula: and pharmaceutically acceptable salts thereof, the substituents of which are defined herein.

[0010] This invention further encompasses ADCs comprising the topoisomerase inhibitors disclosed herein. Both the ADCs and the compounds themselves may be incorporated into pharmaceutical compositions, which are also encompassed by the invention.

[0011] Compounds and compositions disclosed herein may be used in the treatment of various types of cancer, including bladder cancer, brain cancer, breast cancer, colorectal cancer, endometrial cancer, gastric cancer, kidney cancer, liver cancer, lung cancer, ovarian cancer, pancreatic cancer, prostate cancer, and testicular cancer.

[0012] 3. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Certain aspects of the invention may be understood with reference to the accompanying figures.

[0014] FIG. 1 shows a synthetic scheme used to prepare (S)-7-ethyl-7-hydroxy-14-(3- (hydroxymethyl)bicyclo[l. l.l]pentan-l-yl)-7H-[l,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolizino[l,2- b]quinoline-8, 11(1 OH, 13H) -dione .

[0015] FIG. 2 shows a synthetic scheme used to prepare (S)-l l-(3-(2-aminoethoxy)bicyclo[l.l. l]pentan- l-yl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline- 3,14(4H)-dione.

[0016] FIG. 3 shows a synthetic scheme used to prepare (S)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-l 1- (3 -(methylthio)bicyclo [1.1.1 ]pentan- 1 -yl)- 1 , 12-dihydro- 14H-pyrano [3 ',4' : 6,7] indolizino[ 1 ,2-b]quinoline- 3,14(4H)-dione.

[0017] FIG. 4 shows a synthetic scheme used to prepare (S)-l l-(3-(aminomethyl)bicyclo[l.l. l]pentan- l-yl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline- 3,14(4H)-dione.

[0018] FIG. 5 shows a synthetic scheme used to prepare (S)-A-((3-(4-ethyl-8-fluoro-4-hydroxy-9- methyl-3, 14-dioxo-3,4, 12, 14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[ l,2-b]quinolin-l 1- y I jbicyclo [1.1. 1 ]pentan- 1 -yl)methyl)-3 -hydroxypropanamide . TSRI 2255.1PC / CIB0907P 18350.026WO1

[0019] FIG. 6 shows a synthetic scheme used to prepare (S)-2-Amino-N-((2-(((3-(4-ethyl-8-fluoro-4- hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-l 1- yl)bicyclo[l .1. l]pentan-l-yl)methyl)amino)-2 -oxoethoxy )methyl)acetamide.

[0020] 4. DETAILED DESCRIPTION

[0021] This invention is directed to novel and potent topoisomerase inhibitors, ADCs comprising them, compositions comprising them, and methods of their use.

[0022] 4.1. DEFINITIONS

[0023] Unless otherwise indicated, the term “about” means ± 10% of the indicated range.

[0024] The term “acyl” as used herein denotes a group of formula -C(=O)R wherein R is hydrogen or lower alkyl as defined herein. The term or “alkylcarbonyl” as used herein denotes a group of formula C(=O)R wherein R is alkyl as defined herein. The term Ci-6 acyl refers to a group -C(=O)R contain 6 carbon atoms. The term “arylcarbonyl” as used herein means a group of formula C(=O)R wherein R is an aryl group; the term “benzoyl” as used herein an “arylcarbonyl” group wherein R is phenyl.

[0025] The terms “alkenyl” or “olefin” refers to a radical of a straight-chain or branched hydrocarbon group having from 2 to 10 carbon atoms and 1, 2, 3, or 4 carbon-carbon double bonds (“C2-10 alkenyl”). In some embodiments, an alkenyl group has 2 to 9 carbon atoms (“C2-9 alkenyl”). In some embodiments, an alkenyl group has 2 to 8 carbon atoms (“C2-8 alkenyl”). In some embodiments, an alkenyl group has 2 to 7 carbon atoms (“C2-7 alkenyl”). In some embodiments, an alkenyl group has 2 to 6 carbon atoms (“C2-6 alkenyl”). In some embodiments, an alkenyl group has 2 to 5 carbon atoms (“C2-5 alkenyl”). In some embodiments, an alkenyl group has 2 to 4 carbon atoms (”€’2 4 alkenyl”). In some embodiments, an alkenyl group has 2 to 3 carbon atoms (“C2-3 alkenyl”). In some embodiments, an alkenyl group has 2 carbon atoms (“C2 alkenyl”). The one or more carbon-carbon double bonds can be internal (such as in 2- butenyl) or terminal (such as in 1-butenyl). Examples of C? 4 alkenyl groups include ethenyl (C2), 1- propenyl (C3), 2-propenyl (C3), 1-butenyl (C4), 2-butenyl (C4), butadienyl (C4), and the like. Examples of C2-6 alkenyl groups include the aforementioned C 4 alkenyl groups as well as pentenyl (C5), pentadienyl (C5), hexenyl (Ce), and the like. Additional examples of alkenyl include heptenyl (C7), octenyl (Cs), octatrienyl (Cs), and the like.

[0026] The term “alkoxy” as used herein means an -O-alkyl group, wherein alkyl is as defined above such as methoxy, ethoxy, w-propyloxy. z-propyloxy, w-butyloxy. / -butyloxy, / -butyloxy. pentyloxy, hexyloxy, including their isomers. “Lower alkoxy” denotes an alkoxy group with a “lower alkyl” group as previously defined. “C1-10 alkoxy” refers to an-O-alkyl wherein alkyl is CMO.

[0027] The term “alkyl” refers to a radical of a straight-chain or branched saturated hydrocarbon group having from 1 to 20 carbon atoms (“C1-20 alkyl”). In some embodiments, an alkyl group has 1 to 15 carbon atoms (“C1-15 alkyl”). In some embodiments, an alkyl group has 1 to 14 carbon atoms (“C1-14 alkyl”). In some embodiments, an alkyl group has 1 to 13 carbon atoms (“C1-13 alkyl”). In some embodiments, an alkyl group has 1 to 12 carbon atoms (“C1-12 alkyl”). In some embodiments, an alkyl TSRI 2255.1PC / CIB0907P 18350.026WO1 group has 1 to 11 carbon atoms (“Ci-n alkyl”). In some embodiments, an alkyl group has 1 to 10 carbon atoms (“Ci-io alkyl”). In some embodiments, an alkyl group has 1 to 9 carbon atoms (“C1-9 alkyl”). In some embodiments, an alkyl group has 1 to 8 carbon atoms (“Ci-s alkyl”). In some embodiments, an alkyl group has 1 to 7 carbon atoms (“C1-7 alkyl”). In some embodiments, an alkyl group has 1 to 6 carbon atoms (“C1-6 alkyl”). In some embodiments, an alkyl group has 1 to 5 carbon atoms (“C1-5 alkyl”). In some embodiments, an alkyl group has 1 to 4 carbon atoms (“Ci^ alkyl”). In some embodiments, an alkyl group has 1 to 3 carbon atoms (“C1-3 alkyl”). In some embodiments, an alkyl group has 1 to 2 carbon atoms (“C1-2 alkyl”). In some embodiments, an alkyl group has 1 carbon atom (“Ci alkyl”). In some embodiments, an alkyl group has 2 to 6 carbon atoms (“C2-6 alkyl”). Examples of C1-6 alkyl groups include methyl (Ci), ethyl (C2), n-propyl (C3), isopropyl (C3), n-butyl (C4), tert-butyl (C4), sec-butyl (C4), iso-butyl (C4), n-pentyl (C5), 3-pentanyl (C5), amyl (C5), neopentyl (C5), 3-methyl-2-butanyl (C5), tertiary amyl (C5), and n-hexyl (Ce). Additional examples of alkyl groups include n-heptyl (C7), n-octyl (C8) and the like.

[0028] When the term “alkyl” is used as a suffix following another term, as in “phenylalkyl,” or “hydroxyalkyl,” this is intended to refer to an alkyl group, as defined above, being substituted with one to two substituents selected from the other specifically-named group. Thus, for example, “phenylalkyl” denotes the radical R'R"-, wherein R is a phenyl radical, and R" is an alkylene radical as defined herein with the understanding that the attachment point of the phenylalkyl moiety will be on the alkylene radical. Examples of arylalkyl radicals include, but are not limited to, benzyl, phenylethyl, 3 -phenylpropyl. The terms “arylalkyl” or “aralkyl” are interpreted similarly except R is an aryl radical. The terms “(het)arylalkyl” or “(het)aralkyl” are interpreted similarly except R is optionally an aryl or a heteroaryl radical.

[0029] The term “alkylene” or “alkylenyl” as used herein denotes a divalent saturated linear hydrocarbon radical of 1 to 10 carbon atoms (e.g., (CH2)n)or a branched saturated divalent hydrocarbon radical of 2 to 10 carbon atoms (e.g., -CHMe- or -CH2CH(z-Pr)CH2-), unless otherwise indicated. Except in the case of methylene, the open valences of an alkylene group are not attached to the same atom. Examples of alkylene radicals include, but are not limited to, methylene, ethylene, propylene, 2-methyl-propylene, 1,1- dimethyl -ethylene, butylene, 2-ethylbutylene.

[0030] The terms “alkylsulfonyl” and “arylsulfonyl” as used herein refers to a group of formula - S(=O)2R wherein R is alkyl or aryl respectively and alkyl and aryl are as defined herein. The term “heteroalkylsulfonyl” as used herein refers herein denotes a group of formula -S(=O)2R wherein R is “heteroalkyl” as defined herein.

[0031] The terms “alkylsulfonylamino” and “arylsulfonylamino ”as used herein refers to a group of formula -NR'S(=O)2R wherein R is alkyl or aryl respectively, R is hydrogen or C1-3 alkyl, and alkyl and aryl are as defined herein.

[0032] The term “alkynyl” refers to a radical of a straight-chain or branched hydrocarbon group having from 2 to 10 carbon atoms and one or more carbon-carbon triple bonds (e.g., 1, 2, 3, or 4 triple bonds) (“C2-10 alkynyl”). In some embodiments, an alkynyl group has 2 to 9 carbon atoms (“C2-9 alkynyl”). In TSRI 2255.1PC / CIB0907P 18350.026WO1 some embodiments, an alkynyl group has 2 to 8 carbon atoms (“C2-8 alkynyl”). In some embodiments, an alkynyl group has 2 to 7 carbon atoms (“C2-7 alkynyl”). In some embodiments, an alkynyl group has 2 to 6 carbon atoms (“C2-6 alkynyl”). In some embodiments, an alkynyl group has 2 to 5 carbon atoms (“C2-5 alkynyl”). In some embodiments, an alkynyl group has 2 to 4 carbon atoms ("C2 4 alkynyl”). In some embodiments, an alkynyl group has 2 to 3 carbon atoms (“C2-3 alkynyl”). In some embodiments, an alkynyl group has 2 carbon atoms (“C2 alkynyl”). The one or more carbon-carbon triple bonds can be internal (such as in 2-butynyl) or terminal (such as in 1-butynyl). Examples of C? 4 alkynyl groups include, without limitation, ethynyl (C2), 1-propynyl (C3), 2-propynyl (C3), 1-butynyl (C4), 2-butynyl (C4), and the like. Examples of C2-6 alkenyl groups include the aforementioned C 4 alkynyl groups as well as pentynyl (C5), hexynyl (Ce), and the like. Additional examples of alkynyl include heptynyl (C7), octynyl (Cs), and the like.

[0033] The term “aryl” refers to a radical of a monocyclic or polycyclic (e.g., bicyclic or tricyclic) 4n+2 aromatic ring system (e.g., having 6, 10, or 14 pi electrons shared in a cyclic array) having 6-14 ring carbon atoms and zero heteroatoms provided in the aromatic ring system (“Ce-i4 aryl”). In some embodiments, an aryl group has 6 ring carbon atoms (“Ce aryl”; e.g., phenyl). In some embodiments, an aryl group has 10 ring carbon atoms (“Cio aryl”; e.g., naphthyl such as 1-naphthyl (a-naphthyl) and 2- naphthyl ( -naphthyl)). In some embodiments, an aryl group has 14 ring carbon atoms (“C 14 aryl”; e.g., anthracyl). “Aryl” also includes ring systems wherein the aryl ring, as defined above, is fused with one or more carbocyclyl or heterocyclyl groups wherein the radical or point of attachment is on the aryl ring, and in such instances, the number of carbon atoms continue to designate the number of carbon atoms in the aryl ring system.

[0034] Unless otherwise indicated, the term “combination”, when used to describe the administration of two or more drugs to a patient, means that the two or more drugs are administered in a way such that their effects overlap or that one drug will affect the efficacy or safety of a second drug. The two or more drugs need not be administered at the same time or by the same route of administration.

[0035] Carbonyl moieties may be indicated by -C(O)- or -C(=O)-. For example, a carboxylic acid moiety may be represented as -C(O)OH or -C(=O)OH.

[0036] The term “cycloalkyl” refers to a saturated or partially unsaturated all carbon-backbone ring having 3 to 20 carbon atoms (e.g., C3-20, C3-15, C3-7, C4-6 and Ce cycloalkyl). Examples include multicyclic carbocyles such as bicyclo[3.1.0]hexane and bicyclo[2.1.1]hexane, and polycyclic carbocycles, such as tricyclic and tetracyclic carbocycles. The rings of multiple condensed ring systems may be connected to each other via fused, spiro, and bridged bonds when valency allows. For example, multicyclic carbocycles may be connected to each other via a single carbon atom to form a spiro connection (e.g., spiropentane, spiro[4,5]decane), via two adjacent carbon atoms to form a fused connection (e.g. , decahydronaphthalene, norsabinane, norcarane), or via two non-adjacent carbon atoms to form a bridged connection (e.g., norbomane, bicyclo [2.2.2] octane). Examples of cycloalkyls include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, bicyclo[2.2.1]heptane, pinane, adamantane.

[0037] The term “cycloheteroalkyl” refers to a cyclic heteroalkyl moiety, defined below. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0038] The term “halo” encompass fluoro, chloro, bromo, and iodo.

[0039] The terms “haloalkyl” or “halo-lower alkyl” or “lower haloalkyl” refers to a straight or branched chain hydrocarbon residue containing 1 to 6 carbon atoms wherein one or more carbon atoms are substituted with one or more halogen atoms.

[0040] The term “heteroalkyl” refers to a saturated or partially unsaturated moiety having 3- to 20-atom backbone of carbon and at least one heteroatom (e.g., O, N, S). Examples of heteroalkyl moieties include 2-8-membered, 2-6-membered, and 2-4-membered heteroalkyl moieties. Particular examples include alkoxyl, acyl (e.g., formyl, acetyl, benzoyl), alkylamino (e.g., di-(Ci-3-alkyl)amino), arylamino, aryloxime, carbamates, carbamides, alkylcarbonyl, arylcarbonyl, aminocarbonyl, alkylaminocarbonyl, alkylsulfanyl, arylsulfanyl, alkylsulfmyl, arylsulfinyl, alkylsulfonyl, arylsulfonyl, alkylsulfonylamino, and arylsulfonylamino .

[0041] The term “heteroaryl” refers to a radical of a 5-14 membered monocyclic or polycyclic (e.g., bicyclic, tricyclic) 4n+2 aromatic ring system (e.g., having 6, 10, or 14 pi electrons shared in a cyclic array) having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-14 membered heteroaryl”). In heteroaryl groups that contain one or more nitrogen atoms, the point of attachment can be a carbon or nitrogen atom, as valency permits. Heteroaryl polycyclic ring systems can include one or more heteroatoms in one or both rings. “Heteroaryl” includes ring systems wherein the heteroaryl ring, as defined above, is fused with one or more carbocyclyl or heterocyclyl groups wherein the point of attachment is on the heteroaryl ring, and in such instances, the number of ring members continue to designate the number of ring members in the heteroaryl ring system. “Heteroaryl” also includes ring systems wherein the heteroaryl ring, as defined above, is fused with one or more aryl groups wherein the point of attachment is either on the aryl or heteroaryl ring, and in such instances, the number of ring members designates the number of ring members in the fused polycyclic (aryl / heteroaryl) ring system. Polycyclic heteroaryl groups wherein one ring does not contain a heteroatom (e.g., indolyl, quinolinyl, carbazolyl, and the like) the point of attachment can be on either ring, i.e., either the ring bearing a heteroatom (e.g., 2-indolyl) or the ring that does not contain a heteroatom (e.g., 5-indolyl).

[0042] In some embodiments, a heteroaryl group is a 5-10 membered aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-10 membered heteroaryl”). In some embodiments, a heteroaryl group is a 5-8 membered aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-8 membered heteroaryl”). In some embodiments, a heteroaryl group is a 5-6 membered aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-6 membered heteroaryl”). In some embodiments, the 5-6 membered heteroaryl has 1-3 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heteroaryl has 1-2 ring heteroatoms selected from nitrogen, oxygen, and TSRI 2255.1PC / CIB0907P 18350.026WO1 sulfur. In some embodiments, the 5-6 membered heteroaryl has 1 ring heteroatom selected from nitrogen, oxygen, and sulfur.

[0043] Exemplary 5-membered heteroaryl groups containing 1 heteroatom include, without limitation, pyrrolyl, furanyl and thiophenyl. Exemplary 5-membered heteroaryl groups containing 2 heteroatoms include, without limitation, imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, and isothiazolyl. Exemplary 5-membered heteroaryl groups containing 3 heteroatoms include, without limitation, triazolyl, oxadiazolyl, and thiadiazolyl. Exemplary 5-membered heteroaryl groups containing 4 heteroatoms include, without limitation, tetrazolyl. Exemplary 6-membered heteroaryl groups containing 1 heteroatom include, without limitation, pyridinyl. Exemplary 6-membered heteroaryl groups containing 2 heteroatoms include, without limitation, pyridazinyl, pyrimidinyl, and pyrazinyl. Exemplary 6-membered heteroaryl groups containing 3 or 4 heteroatoms include, without limitation, triazinyl and tetrazinyl, respectively. Exemplary 7-membered heteroaryl groups containing 1 heteroatom include, without limitation, azepinyl, oxepinyl, and thiepinyl. Exemplary 5,6-bicyclic heteroaryl groups include, without limitation, indolyl, isoindolyl, indazolyl, benzotriazolyl, benzothiophenyl, isobenzothiophenyl, benzofuranyl, benzoisofuranyl, benzimidazolyl, benzoxazolyl, benzisoxazolyl, benzoxadiazolyl, benzthiazolyl, benzisothiazolyl, benzthiadiazolyl, indolizinyl, and purinyl. Exemplary 6,6-bicyclic heteroaryl groups include, without limitation, naphthyridinyl, pteridinyl, quinolinyl, isoquinolinyl, cinnolinyl, quinoxalinyl, phthalazinyl, and quinazolinyl. Exemplary tricyclic heteroaryl groups include, without limitation, phenanthridinyl, dibenzofuranyl, carbazolyl, acridinyl, phenothiazinyl, phenoxazinyl and phenazinyl.

[0044] The terms “heterocyclyl” and “heterocyclic” refer to a group or radical of a 3- to 14-membered non-aromatic ring system having ring carbon atoms and 1 to 4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“3-14 membered heterocyclyl”). In heterocyclyl groups that contain one or more nitrogen atoms, the point of attachment can be a carbon or nitrogen atom, as valency permits. A heterocyclyl group can either be monocyclic (“monocyclic heterocyclyl”) or polycyclic (e.g., a fused, bridged or spiro ring system such as a bicyclic system (“bicyclic heterocyclyl”) or tricyclic system (“tricyclic heterocyclyl”)), and can be saturated or can contain one or more carbon-carbon double or triple bonds. Heterocyclyl polycyclic ring systems can include one or more heteroatoms in one or both rings. “Heterocyclyl” also includes ring systems wherein the heterocyclyl ring, as defined above, is fused with one or more carbocyclyl groups wherein the point of attachment is either on the carbocyclyl or heterocyclyl ring, or ring systems wherein the heterocyclyl ring, as defined above, is fused with one or more aryl or heteroaryl groups, wherein the point of attachment is on the heterocyclyl ring, and in such instances, the number of ring members continue to designate the number of ring members in the heterocyclyl ring system.

[0045] In some embodiments, a heterocyclyl group is a 5-10 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-10 membered heterocyclyl”). In some embodiments, a heterocyclyl group is a 5-8 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, TSRI 2255.1PC / CIB0907P 18350.026WO1 wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-8 membered heterocyclyl”). In some embodiments, a heterocyclyl group is a 5-6 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-6 membered heterocyclyl”). In some embodiments, the 5-6 membered heterocyclyl has 1-3 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heterocyclyl has 1-2 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heterocyclyl has 1 ring heteroatom selected from nitrogen, oxygen, and sulfur.

[0046] Exemplary 3-membered heterocyclyl groups containing 1 heteroatom include, without limitation, azirdinyl, oxiranyl, and thiiranyl. Exemplary 4-membered heterocyclyl groups containing 1 heteroatom include, without limitation, azetidinyl, oxetanyl and thietanyl. Exemplary 5-membered heterocyclyl groups containing 1 heteroatom include, without limitation, tetrahydrofuranyl, dihydrofuranyl, tetrahydrothiophenyl, dihydrothiophenyl, pyrrolidinyl, dihydropyrrolyl, and pyrrolyl-2, 5-dione. Exemplary 5-membered heterocyclyl groups containing 2 heteroatoms include, without limitation, dioxolanyl, oxathiolanyl and dithiolanyl. Exemplary 5-membered heterocyclyl groups containing 3 heteroatoms include, without limitation, triazolinyl, oxadiazolinyl, and thiadiazolinyl. Exemplary 6- membered heterocyclyl groups containing 1 heteroatom include, without limitation, piperidinyl, tetrahydropyranyl, dihydropyridinyl, and thianyl. Exemplary 6-membered heterocyclyl groups containing 2 heteroatoms include, without limitation, piperazinyl, morpholinyl, dithianyl, and dioxanyl. Exemplary 6-membered heterocyclyl groups containing 3 heteroatoms include, without limitation, triazinanyl. Exemplary 7-membered heterocyclyl groups containing 1 heteroatom include, without limitation, azepanyl, oxepanyl and thiepanyl. Exemplary 8-membered heterocyclyl groups containing 1 heteroatom include, without limitation, azocanyl, oxecanyl and thiocanyl. Exemplary bicyclic heterocyclyl groups include, without limitation, indolinyl, isoindolinyl, dihydrobenzofuranyl, dihydrobenzothienyl, tetrahydrobenzothienyl, tetrahydrobenzofuranyl, tetrahydroindolyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, decahydroquinolinyl, decahydroisoquinolinyl, octahydrochromenyl, octahydroisochromenyl, decahydronaphthyridinyl, decahydro- 1,8-naphthyridinyl, octahydropyrrolo[3,2- b]pyrrole, indolinyl, phthalimidyl, naphthalimidyl, chromanyl, chromenyl, lH-benzo[e][l,4]diazepinyl, 1 ,4,5 ,7-tetrahydropyrano [3 ,4-b]pyrrolyl, 5 ,6-dihydro-4H-furo [3 ,2-b]pyrrolyl, 6,7-dihydro-5H-furo- [3,2-b]pyranyl, 5,7-dihydro-4H-thieno[2,3-c]pyranyl, 2,3-dihydro-lH-pyrrolo[2,3-b]pyridinyl, 2,3- dihydrofuro[2,3-b]pyridinyl, 4,5,6,7-tetrahydro-lH-pyrrolo[2,3-b]pyridinyl, 4,5,6,7-tetrahydrofuro[3,2- c]pyridinyl, 4,5,6,7-tetrahydrothieno[3,2-b]pyridinyl, l,2,3,4-tetrahydro-l,6-naphthyridinyl, and the like.

[0047] The term “heterocycloalkyl” refers to a cyclic (monocyclic or polycyclic) heteroalkyl.

[0048] The term “hydroxyalkyl” as used herein denotes an alkyl radical as herein defined wherein one to three hydrogen atoms on different carbon atoms is / are replaced by hydroxyl groups. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0049] The term “include” has the same meaning as “include, but are not limited to,” and the term “includes” has the same meaning as “includes, but is not limited to.” Similarly, the term “such as” has the same meaning as the term “such as, but not limited to.”

[0050] The term “lower alkyl” refers to alkyl having from 1 to 6 carbon atoms, e.g., Ci-4 alkyl. Examples include methyl, ethyl, propyl, isopropyl, and cyclobutyl.

[0051] The terms “manage,” “managing” and “management” mean preventing the recurrence of the specified disease or disorder in a patient who has already suffered from the disease or disorder, and / or lengthening the time that a patient who has suffered from the disease or disorder remains in remission. The terms encompass modulating the threshold, development and / or duration of the disease or disorder or changing the way that a patient responds to the disease or disorder.

[0052] The term “pharmaceutically acceptable salt” refers to a salt that is generally recognized as safe to administer to a subject. Examples of pharmaceutically acceptable salts include acetate, chloride, diphosphate, hydrochloride, maleate, phosphate, potassium, sodium, and sulfate.

[0053] The terms “prevent,” “preventing” and “prevention” contemplate an action that occurs before a patient begins to suffer from the specified disease or disorder, which inhibits or reduces the severity of the disease or disorder. The terms encompass prophylaxis.

[0054] A “prophylactically effective amount” of a compound is an amount sufficient to prevent a disease or condition, or one or more symptoms associated with the disease or condition, or prevent its recurrence. A “prophylactically effective amount” of a compound means an amount, alone or in combination with other agents, that provides a prophylactic benefit in the prevention of the disease. The term “prophylactically effective amount” can encompass an amount that improves overall prophylaxis or enhances the prophylactic efficacy of another prophylactic agent.

[0055] The terms “subject” and “patient” are used interchangeably. The terms “subject” and “subjects” refer to an animal, such as a non-primate mammal (e.g., cow, pig, horse, cat, dog, rat, and mouse) and a primate (e.g., monkey, a chimpanzee, human). Preferred subjects are human (e.g, adult humans).

[0056] A “therapeutically effective amount” of a compound is an amount sufficient to provide a therapeutic benefit in the treatment or management of a disease or condition, or to delay or minimize one or more symptoms associated with the disease or condition. A “therapeutically effective amount” of a compound means an amount, alone or in combination with other therapies, that provides a therapeutic benefit in the treatment or management of the disease or condition. The term “therapeutically effective amount” can encompass an amount that improves overall therapy, reduces, or avoids symptoms or causes of a disease or condition, or enhances the therapeutic efficacy of another therapeutic agent.

[0057] The terms “treat,” “treating” and “treatment” contemplate an action that occurs while a patient is suffering from a specified disease or disorder, which reduces the severity of the disease or disorder or retards or slows the progression of the disease or disorder.

[0058] The definitions described herein may be appended to form chemically-relevant combinations, such as “heteroalkylaryl,” “haloalkylheteroaryl,” “arylalkylheterocyclyl,” “alkylcarbonyl,” “alkoxyalkyl,” and the like. When the term “alkyl” is used as a suffix following another term, as in “phenylalkyl,” or TSRI 2255.1PC / CIB0907P 18350.026WO1

[0059] “hydroxyalkyl,” this is intended to refer to an alkyl group, as defined above, being substituted with one to two substituents selected from the other specifically-named group. Thus, for example, “phenylalkyl” refers to an alkyl group having one to two phenyl substituents, and thus includes benzyl, phenylethyl, and biphenyl. An “alkylaminoalkyl” is an alkyl group having one to two alkylamino substituents. “Hydroxyalkyl” includes 2-hydroxyethyl, 2-hydroxypropyl, 1 -(hydroxymethyl) -2 -methylpropyl, 2- hydroxybutyl, 2,3 -dihydroxybutyl, 2-(hydroxymethyl), 3 -hydroxypropyl, and so forth. Accordingly, as used herein, the term “hydroxyalkyl” is used to define a subset of heteroalkyl groups defined below. The term -(ar)alkyl refers to either an unsubstituted alkyl or an aralkyl group. The term (hetero)aryl or (het)aryl refers to either an aryl or a heteroaryl group.

[0060] Unless otherwise indicated, an adjective before a string of nouns should be construed to apply to each. For example, the phrase “optionally substituted pyridyl, pyrazyl, or furanyl” means the same as “optionally substituted pyridyl, optionally substituted pyrazyl, or optionally substituted furanyl”.

[0061] A dashed line “ — ” used to depict a bond in a chemical structure indicates that the bond may be delocalized (e.g. , as in a tautomer) or may or may not exist (e.g. , as in the case where a solid and a dashed line are used together to depict a bond that may exist as a single bond or a double bond).

[0062] A wavy line ” that intersects a bond in a chemical structure indicates the point of attachment of the bond that the wavy bond intersects in the chemical structure to the remainder of a molecule.

[0063] Compounds disclosed herein may exist as tautomeric isomers. Although only one delocalized resonance structure may be depicted, all such forms are contemplated within the scope of the invention.

[0064] Compounds disclosed herein may exist as zwitterions (e.g., at pharmacological pH). Unless otherwise indicated, it should be understood that a chemical drawing depicting the structure of such a compound encompasses all of its zwitterionic forms.

[0065] When a range of values is listed, it is intended to encompass each value and sub-range within the range. For example, “Ci-6 alkyl” is intended to encompass, Ci, C2, C3, C4, C5, Ce, C1-6, C1-5, Ci^, C1-3, C1-2, C2-6, C2-5, C2 4. C2-3, C3-6, C3-5, C3 4. C4-6, C4-5, and C5-6 alkyl.

[0066] Some compounds may exist as stereoisomers. When a stereoisomer of compound is defined by its name (e.g. , with the use of R or .S') or is depicted in a drawn structure (e.g. , using a bold, bold-wedge, dashed, or dashed-wedge to depict the relevant chemical bond), the enantiomeric excess (ee) of that compound, unless otherwise indicated, is to be understood to be at least 60, 70, 80, 90, 95, or 99%. A compound or composition enriched with one stereoisomer of the compound has that one stereoisomer in an amount measurably greater than the compound’s other stereoisomer(s). For example, a compound enriched with an R enantiomer will have an enantiomeric excess of that enantiomer versus the S enantiomer. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0067] 4.2. COMPOUNDS OF THE INVENTION

[0068] This invention is directed, in part, to topoisomerase inhibitors of formula I: and pharmaceutically acceptable salt thereof, wherein:

[0069] X is O or S;

[0070] R1is H, halo, R1A, -OR1A, -SR1A, or -S(O)2R1A;

[0071] R1Ais optionally substituted (Ci-Ce) alkyl, (Ci-Ce) heteroalkyl, (C3-C10) cycloalkyl, (C2-C10) heterocycloalkyl, (C6-Cio) aryl, (C5-C10) heteroaryl, -C(O)(Ci-C6) alkyl, -(Ci-C6) alkyl-NHC(O)-(Ci-C6) alkyl, -(Ci-Ce) alkyl-NHC(O)O-(Ci-C6) alkyl, -(Ci-C6) alkyl-O(Ci-C6) alkyl-NH-C(O)-(Ci-C6) alkyl, or -(Ci-Ce) alkyl-O(Ci-Ce) alkyl-NH-C(O)O-(Ci-Ce) alkyl, which optional substitution is with one or more R1B; each R1Bis independently halo, hydroxy, NO2, R1C, -OR1C, -SR1C, -C(O)Rlc, or -NRBRC; each R1Cis independently H or optionally substituted (Ci-Ce) alkyl, (Ci-Ce) heteroalkyl, (Cs-Cs) cycloalkyl, (C2-Cs) heterocycloalkyl, (Ce-Cio) aryl, or (C5-C10) heteroaryl, which optional substitution is with one or more of halo, hydroxy, NO2, -NHC(O)RA, or -NRBRC;

[0072] R2is H, halo, RA, -ORA, or -NRBRC;

[0073] R3is H, halo, RA, -ORA, -NRBRC, or -NRBC(O)RA;

[0074] R4is H, halo, RA, -ORA, or -NRBRC;

[0075] R5is H, halo, RA, -ORA, or -NRBRC; each RAis independently H or optionally substituted (Ci-Ce) alkyl or (Cs-Cs) cycloalkyl, which optional substitution is with one or more of halo, hydroxy, or -NRBRC; and each of RBand Rcis independently H or optionally substituted -(Ci-Ce) alkyl, -C(O)-(Ci-Ce) alkyl, or -C(O)O-(Ci-Ce) alkyl, which optional substitution is with one or more of amino, halo, or hydroxy; or R2and R3together form a ring, which ring is (C3-C7) cycloalkyl, (C2-Ce) heterocycloalkyl, (Ce- C10) aryl, or (C5-C10) heteroaryl; or R3and R4together form a ring, which ring is (C3-C7) cycloalkyl, (C2-Ce) heterocycloalkyl, (Ce- C10) aryl, or (C5-C10) heteroaryl; or R4and R5together form a ring, which ring is (C3-C7) cycloalkyl, (C2-Ce) heterocycloalkyl, (Ce- C10) aryl, or (C5-C10) heteroaryl. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0076] In some embodiments of the invention, R2and R3do not form a ring. In some embodiments, R3and R4do not form a ring. In some embodiments, R4and R5do not form a ring.

[0077] In some embodiments, X is O. In others, X is S.

[0078] In some embodiments, R1is H or halo. In some embodiments, R1is R1A. In some embodiments, R1is -OR1A. In some embodiments, R1is -SR1Aor -S(O)2R1A.

[0079] In some embodiments, R1Ais (Ci-Ce) alkyl. In some embodiments, R1Ais optionally substituted - (Ci-C6) alkyl-NHC(O)-(Ci-C6) alkyl, -(Ci-C6) alkyl-NHC(O)O-(Ci-C6) alkyl, -(Ci-C6) alkyl-O(Ci-C6) alkyl-NH-C(O)-(Ci-C6) alkyl, or -(Ci-C6) alkyl-O(Ci-C6) alkyl-NH-C(O)O-(Ci-C6) alkyl, which optional substitution is with one or more R1B.

[0080] In some embodiments, R1Bis -NRBRC.

[0081] In some embodiments, if R1is -CH2OH and R3is methyl or methoxy, R4is not fluoro.

[0082] In some embodiments, R2is H.

[0083] In some embodiments, R3is RA. In some embodiments, R3is -ORA. In some embodiments, if R3is methyl or methoxy, R4is not fluoro. In some embodiments, R3is -NRBC(O)RA.

[0084] In some embodiments, RAis H or -(Ci-Ce) alkyl. In some embodiments, RAis -(Ci-Ce) alkyl optionally substituted with -NRBRCor hydroxy.

[0085] In some embodiments, R3is -NRBRC.

[0086] In some embodiments, RBis H. In some embodiments, RBis -(Ci-Ce) alkyl optionally substituted with hydroxy.

[0087] In some embodiments, Rcis H. In some embodiments, Rcis -(Ci-Ce) alkyl.

[0088] In some embodiments, each of RBand Rcis H.

[0089] In some embodiments, R4is halo.

[0090] In some embodiments, R5is H.

[0091] In some embodiments, R2and R3together form a ring.

[0092] In some embodiments, R3and R4together form a ring.

[0093] In some embodiments, R4and R5together form a ring.

[0094] In some embodiments, the ring formed by R2and R3, by R3and R4, or by R4and R5is (C2-Ce) heterocycloalkyl. In some embodiments, the ring is 1,3 -dioxolane. In some embodiments, the ring is not 1,3 -dioxolane.

[0095] In some embodiments, if the ring is 1,3 -dioxolane, R1is not R1Aor -OR1A.

[0096] In some embodiments, X is O, R1is -OR1A, and R1Ais optionally substituted -(Ci-Ce) alkyl. In some embodiments, R2is H and R5is H. In some embodiments, R3is RAand RAis -NRBRC. In some embodiments, RBis H. In some embodiments, Rcis H. In some embodiments, R4is halo. In some embodiments, R5is H.

[0097] Particular compounds of the invention are:

[0098] (S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3-(hydroxymethyl)bicyclo[l.l. l]pentan-l-yl)-9-methyl-l,12- dihydro- 14H-pyrano [3', 4' : 6,7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H) -dione ; TSRI 2255.1PC / CIB0907P 18350.026WO1

[0099] (S)-4-ethyl-8,9-difluoro-4-hydroxy- 11 -(3 -(hydroxymethyl)bicyclo [1.1.1 ]pentan- 1 -yl)- 1,12- dihydro- 14H-pyrano [3', 4' : 6,7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H) -dione ;

[0100] (S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3-(hydroxymethyl)bicyclo[l.l.l]pentan-l-yl)-9-methoxy- 1 , 12-dihydro- 14H-pyrano [3 ',4' : 6, 7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H)-dione;

[0101] (S)-7-ethyl-7-hydroxy-14-(3-(hydroxymethyl)bicyclo[l.l.l]pentan-l-yl)-10,13-dihydro-l 1H-

[0102] [1.3]dioxolo[4,5-g]pyrano[3',4':6,7]indolizino[l,2-b]quinoline-8,l l(7H)-dione;

[0103] (S)-8-ethyl-8-hydroxy-15-(3-(hydroxymethyl)bicyclo[l.l.l]pentan-l-yl)-ll,14-dihydro-12H-

[0104] [1.3]dioxolo[4,5-f]pyrano[3',4':6,7]indolizino[l,2-b]quinoline-9,12(8H)-dione;

[0105] (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy- 11 -(3 -methylbicyclo [1.1.1 ]pentan- 1 -yl)- 1 , 12-dihydro- 14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione;

[0106] (S)-9-amino-l 1 -(bicyclo [1.1. l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-l, 12-dihydro-14H- pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione;

[0107] (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy- 11 -(3 -methoxybicyclo [1.1.1 ]pentan- 1 -yl)- 1 , 12-dihydro- 14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione;

[0108] (S)-9-amino-4-ethyl-8-fluoro-l 1 -(3 -fluorobicyclo [1.1. l]pentan-l-yl)-4-hydroxy-l, 12-dihydro- 14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione;

[0109] (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-l 1 -(3 -methoxybicyclo [1.1. l]pentan-l-yl)-14-thioxo- 12,14-dihydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-3(4H)-one;

[0110] (R)-14-(bicyclo[l.l.l]pentan-l-yl)-7-ethyl-7-hydroxy-10,13-dihydro-l lH-[l,3]dioxolo[4,5- g]pyrano[3',4':6,7]indolizino[l,2-b]quinoline-8,l l(7H)-dione;

[0111] (S)-2-amino-N-(((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH- pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l-yl)methoxy)methyl)acetamide;

[0112] (S)-2-amino-N-(2-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH- pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l-yl)oxy)ethyl)acetamide;

[0113] (S)-l 1 -(3-(2 -aminoethoxy )bicy clo[ 1.1. l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-l, 12- dihydro- 14H-pyrano [3', 4' : 6,7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H) -dione ;

[0114] 2-hydroxyethyl (S)-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3, 14-dioxo-3,4, 12, 14-tetrahydro- IH-pyrano [3 ',4' : 6,7]indolizino [ 1 ,2-b] quinolin- 11 -yl)bicyclo [1.1.1 ]pentan- 1 -yl)methyl)carbamate;

[0115] (S)-N-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH- pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l-yl)methyl)-3- hydroxypropanamide ;

[0116] (S)-N-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH- pyrano[3', 4':6, 7] indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l-yl)methyl)-2 -hydroxyacetamide;

[0117] (S)-l l-(3-(aminomethyl)bicyclo[l.l.l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-l,12- dihydro- 14H-pyrano [3', 4' : 6,7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H) -dione ;

[0118] (S)-2-amino-N-((2-(((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3, 14-dioxo-3,4, 12, 14-tetrahydro- IH-pyrano [3 ',4' : 6,7]indolizino [ 1 ,2-b] quinolin- 11 -yl)bicyclo [1.1.1 ]pentan- 1 -yl)methyl)amino)-2- oxoethoxy)methyl)acetamide ; TSRI 2255.1PC / CIB0907P 18350.026WO1

[0119] (S)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-l l-(3-(methylthio)bicyclo[l .1. l]pentan-l-yl)-l, 12- dihydro- 14H-pyrano [3', 4' : 6,7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H) -dione ;

[0120] (S)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-l l-(3-(methylsulfonyl)bicyclo[l .1. l]pentan-l-yl)-

[0121] 1 , 12-dihydro- 14H-pyrano [3 ',4' : 6, 7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H)-dione;

[0122] (S)-N-(4-ethyl-8-fluoro-4-hydroxy- 11 -(3 -methoxybicyclo [ 1.1. l]pentan-l-yl)-3, 14-dioxo-

[0123] 3.4.12.14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)-3-hydroxypropanamide;

[0124] (S)-4-ethyl-8-fluoro-4-hydroxy-9-((2-hydroxyethyl)amino)- 11 -(3 -methoxybicyclo [ 1.1. l]pentan-

[0125] 1 -yl)- 1 , 12-dihydro- 14H-pyrano [3 ',4' : 6,7]indolizino [ 1 ,2-b] quinoline-3 , 14(4H)-dione ;

[0126] (R)-N-((S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3,14-dioxo-

[0127] 3.4.12.14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)-2-hydroxypropanamide;

[0128] (S)-N-((S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3,14-dioxo-

[0129] 3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)-2-hydroxypropanamide;

[0130] (S)-2-amino-N-((S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3,14- dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)propenamide;

[0131] (S)-2-amino-N-((S)-4-ethyl-8-fluoro-4-hydroxy-l 1 -(3 -methoxybicyclo [1.1. l]pentan-l-yl)-3-oxo- 14-thioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)propenamide;

[0132] (R)-N-((S)-4-ethyl-8-fluoro-4-hydroxy-l 1 -(3 -methoxybicyclo [1.1. l]pentan-l-yl)-3-oxo-14- thioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)-2-hydroxypropanamide;

[0133] (S)-4-ethyl-8-fluoro-4-hydroxy-9-(((R)-2-hydroxypropyl)amino)-l l-(3- methoxybicyclo[l.l.l]pentan-l-yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline- 3,14(4H)-dione;

[0134] (S)-4-ethyl-8-fluoro-4-hydroxy-9-(((S)-2-hydroxypropyl)amino)-l l-(3- methoxybicyclo[l.l.l]pentan-l-yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline- 3,14(4H)-dione; and pharmaceutically acceptable salts thereof.

[0135] 4.3. ANTIBODY DRUG CONJUGATES

[0136] The topoisomerase inhibitors disclosed herein may be used as drugs, or “payloads”, in antibody drug conjugates (ADCs). A particular ADC is of the formula:

[0137] Ab-(L-X)„ wherein: Ab is a monoclonal antibody or antibody fragment; L is a cleavable linker; X is a topoisomerase inhibitor, and n is 1-10 (e.g., 2-8, 4-6). The linker L may have multiple parts, referred to below as La, Lb, Lc, and A.

[0138] Compounds of the invention can be conjugated to an ADC linker by coupling the linker to an appropriate part (e.g., an amine) of the R1or R3moiety through an optional connector using methods known in the art to provide ADCs such as those represented below: TSRI 2255.1PC / CIB0907P 18350.026WO1 wherein: Ab is a cancer antigen-targeting antibody; Lais a conjugation moiety through which the Ab is attached to Lb; Lbis a linker that optionally contains one or more hydrophilic groups; Lcis a cleavable linker that optionally contains one or more hydrophilic groups; and Z is an optional group that connects Lcto the pay load.

[0139] Representative examples of Lainclude: Examples of Lbinclude alkynyl, vinyl, O, S, 3-8-membered heterocycles, (CR'R")n, NR'm, and

[0140] CONR', wherein each of R' and R" is independently H or alkyl optionally substituted with one or more hydrophilic groups.

[0141] Examples of hydrophilic groups include: poly PEG (0-24 units), polysarcosine (0-24 units), and polyhydroxyl -containing amines such as:

[0142] Linkers used in ADCs are generally cleavable so that they release their payloads near or at the target (e.g., in a tumor microenvironment). Examples of cleavable linkers are well known in the art. See, e.g., Sheyi R., et al., “An Assurance for Controlled Delivery of Antibody-Drug Conjugate” TSRI 2255.1PC / CIB0907P 18350.026WO1

[0143] Pharmaceutics (2022) 14(2):396; and Wharton T. and Spring DR., “Advances in the Release of Amide- Containing Molecules” Chemistry (2025) 31(16).

[0144] Cleavable linkers (e.g., Lc) may be chemically or enzymatically cleavable. Chemically cleavable linkers are sensitive to environmental factors, such as pH and reduction. Enzymatically cleavable linkers include peptide-based linkers that are susceptible to proteolysis, p -glucuronide -based linkers (e.g., P-glucuronidase sensitive linkers), -galactosidase sensitive linkers, phosphate linkers (e.g., phosphatase sensitive linkers), and carbamates and esters, which are sensitive to esterase cleavage.

[0145] Particular cleavable linkers useful in embodiments of this invention include linkers sensitive to reductive environments (e.g., disulfide bonds), acidic pH (e.g., hydrazones, maleamic acid linkers) and linkers sensitive to esterase cleavage (e.g., esters), cathepsin cleavage (e.g., amides), and -glucuronidase.

[0146] Examples of some cleavable linkers include: reduction sensitive linkers containing a disulfide, pyridyl disulfide, or dithiobenzyl moiety; pH-sensitive linkers containing an acetone hydrazone, benzaldehyde hydrazone, N-(2-hydroxyethyl)maleamic acid, N-(2-aminoethyl)maleamic acid, cis- aconityl, 1,2-diol-based acetal, p-methoxybenzaldehyde acetal, imine / Schiff base, or oxazolidine moiety; esterase sensitive linkers containing a simple ester (e.g., succinate, glutarate ester), p-aminobenzyl ester (PAB ester), acetoxymethyl ester (AM ester), phenyl ester, or benzyl ester moiety; protease sensitive linkers containing a valine-citrulline or valine-alanine (Val-Cit, Vai-Ala) moiety, Gly-Gly-Phe-Gly (GGFG), Gly-Phe-Leu-Gly, Pro-Leu-Gly-Leu-Ala-Gly, or Ala-Ala-Asn moiety; and other enzyme sensitive linkers containing a p-aminobenzyl glucuronide, galactosyl carbamate, or phosphate ester moiety. To increase the hydrophilicity of the linker payload and the ADC, an optional hydrophilic group is introduced at the cleavable linkers of the above example.

[0147] The optional connector Z may be required to ensure proper connection of the payload with the cleavable linker and / or to ensure that the cleavage occurs smoothly in the tumor environment. Examples of Z include para-aminobenzyl carbamate (PABC) and aminomethyl. Optionally one or more hydrophilic groups described above is present at the Z moiety to increase its hydrophilicity.

[0148] The monoclonal antibody — or portion or derivative thereof (e.g., Fab, Fab', F(ab')2, Fd, Fv) — to which the linker is attached will depend on the cancer being targeted. Antibodies suitable for use in this invention include, for example, those that recognize: Alkaline Phosphatase Placental-like 2 (ALPPL2); B7 homolog 3 (B7-H3); B7 homolog 4 (B7-H4); Cadherin 6 (CDH6); Claudin 6 (CLDN6); Claudin 18 isoform 2 (CLDN18.2); Cluster of Differentiation 30 (CD30); CUB Domain Containing Protein 1 (CDCP1); Delta-like protein 3 (DLL3); Epidermal Growth Factor Receptor (EGFR); Folate Receptor Alpha (FRa); Glypican 3 (GPC3); Human Epidermal Growth Factor Receptor 2 (HER2); Human Epidermal Growth Factor Receptor 3 (HER3); Interleukin-3 receptor alpha chain (CD 123); Mesenchymal-Epithelial Transition factor (cMet); Mesothelin (MSLN); Nectin-4; Prostate-Specific Membrane Antigen (PSMA); Programmed Death-Ligand 1 (PD-L1); Tissue Factor (TF); Six- Transmembrane Epithelial Antigen of the Prostate 1 (STEAP1); Trophoblast cell surface antigen 2 (TROP2); and Tumor-Associated Calcium Signal Transducer 2 (TROP2). TSRI 2255.1PC / CIB0907P 18350.026WO1

[0149] 4.4. METHODS OF USE

[0150] This invention encompasses methods of killing cancer cells which comprise contacting a cancer cell (in vitro or in vivo) with a compound of the invention.

[0151] This invention also encompasses a method of treating cancer, which comprises administering to a patient a therapeutically effective amount of a compound of the invention. Examples of cancers include bladder cancer, brain cancer, breast cancer, colorectal cancer, endometrial cancer, gastric cancer, kidney cancer, liver cancer, lung cancer, ovarian cancer, pancreatic cancer, prostate cancer, and testicular cancer.

[0152] In some embodiments, the invention is administered in a pharmaceutically acceptable dosage form. In others, the compound is administered as an ADC (e.g., in a pharmaceutically acceptable vehicle).

[0153] In some embodiments, the compound is administered in combination with another therapeutic agent. Therapeutic agents include other anti -cancer drugs, anti-emetics, and pain relievers (e.g., NSAIDS).

[0154] 4.5. PHARMACEUTICAL FORMULATIONS

[0155] Compounds disclosed herein may be systemically administered in combination with a pharmaceutically acceptable vehicle such as an inert diluent or an assimilable, edible carrier. They may be in the form of single unit dosage forms (e.g., enclosed in hard or soft shell gelatin capsules or compressed into tablets). For oral therapeutic administration, an active compound may be combined with one or more excipients in the form of ingestible tablets, buccal tablets, capsules, caplets, troches, elixirs, suspensions, syrups, and wafers.

[0156] Compounds may also be administered intravenously or intraperitoneally by infusion or injection. Solutions of an active compound or its salts may be prepared in water, optionally mixed with a nontoxic surfactant. Dispersions can also be prepared in glycerol, liquid polyethylene glycols, triacetin, and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations contain a preservative to prevent the growth of microorganisms.

[0157] Pharmaceutical dosage forms suitable for injection or infusion may include sterile aqueous solutions or dispersions or sterile powders comprising the active ingredient which are adapted for the extemporaneous preparation of sterile injectable or infusible solutions or dispersions, optionally encapsulated in liposomes. In all cases, the ultimate dosage form should be sterile, fluid and stable under the conditions of manufacture and storage. The liquid carrier or vehicle can be a solvent or liquid dispersion medium comprising, for example, water, ethanol, a polyol (for example, glycerol, propylene glycol, liquid polyethylene glycols, and the like), vegetable oils, nontoxic glyceryl esters, and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the formation of liposomes, by the maintenance of the required particle size in the case of dispersions or by the use of surfactants. The prevention of the action of microorganisms can be brought about by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars, buffers or sodium chloride. Prolonged TSRI 2255.1PC / CIB0907P 18350.026WO1 absorption of the injectable compositions can be brought about by the use in the compositions of agents delaying absorption, for example, aluminum monostearate and gelatin.

[0158] Sterile injectable solutions are prepared by incorporating the active compound in the required amount in the appropriate solvent with various of the other ingredients enumerated above, as required, followed by filter sterilization. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and the freeze drying techniques, which yield a powder of the active ingredient plus any additional desired ingredient present in the previously sterile-filtered solutions.

[0159] 4.6. EXAMPLES The following examples include descriptions of the synthesis and characterization of specific compounds of the invention, methods used to measure their cytotoxicity, and results obtained using those methods. Some abbreviations used in the examples are defined below:

[0160] Table 1 TSRI 2255.1PC / CIB0907P 18350.026WO1

[0161] 4.6.1. 3-(((Ter / -butyldiphenylsilyl)oxy)methyl)bicyclo[l.l.l]pentane-l-carbaldehyde

[0162] Step 1. A mixture of methyl 3-(hydroxymethyl)bicyclo[l. l.l]pentane-l-carboxylate (7.70 g, 49.4 mmol) imidazole (6.71 g, 98.8 mmol) and TBDPSC1 (tert-Butyl(chloro)diphenylsilane, 16.28 g, 59.2 mmol) in DMF (150 mL) was stirred at room temperature overnight. The reaction mixture was diluted with water (500 mL) and extracted with ethyl acetate (300 mL x 2). The combined organic layers were washed with brine (200 mL x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo The resulting residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 50 to 1 / 20) to give 3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l.l. l]pentane-l-carboxylate (17.6 g, 90% yield) as a colorless oil. ’H-NMR (400 MHz, CD3C1): 5 7.65-7.62 (m, 4H), 7.42-7.26 (m, 6H), 3.67

[0163] (s, 3H), 3.65 (s, 2H), 1.94 (s, 6H), 1.05 (s, 9H). TSRI 2255.1PC / CIB0907P 18350.026WO1

[0164] Step 2. To a solution of 3-(((tert-butyldiphenylsdyl)oxy)methyl)bicyclo[l.l. l]pentane-l- carboxylate (19.6 g, 49.75 mmol) in anhydrous THF (300 mb) was added LiAlH4 (2.5 M in THF) (23.9 mb, 59.70 mmol) dropwise at 0 °C and the mixture was stirred at 0 °C for 1 h. It was diluted with THF (300 mb), and water (2.5 mL) was added dropwise and stirred for 15 min. Aqueous NaOH (15% wt, 2.5 mb) was added dropwise and stirred for 15 min, and water (7.5 mL) was added dropwise and stirred for 15 min. Finally, the mixture was dried over anhydrous magnesium sulfate, fdtered and concentrated in vacuo to give (3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l.l.l]pentan-l-yl)methanol (16.7 g, 92% yield) as a white solid. ’H-NMR (400 MHz, CD3C1): 5 7.66-7.64 (m, 4H), 7.42-7.26 (m, 6H), 3.66 (s, 2H), 3.60 (s, 2H), 1.60 (s, 6H), 1.05 (s, 9H).

[0165] Step 3. To a solution of (3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l.l. l]pentan-l- yl)methanol (6.70 g, 18.31 mmol) in DCM (130 mL) was added PCC (6.70 g, 18.31 mmol) in portions at 0 °C and the reaction flask was warmed to room temperature for 2 h. The precipitate was removed by fdtration through the Celite. The fdtrate was washed with brine (50 mL x 2), dried over anhydrous sodium sulfate, fdtered, and concentrated in vacuo. The resulting residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 50 to 1 / 20) to give 3-(((tert- butyldiphenylsilyl)oxy)methyl)bicyclo[l.l.l]pentane-l-carbaldehyde (4.88 g, 73% yield) as a colorless oil. ’H-NMR (400 MHz, CD3C1): 5 9.57 (s, 1H), 7.65-7.63 (m, 4H), 7.43-7.26 (m, 6H), 3.67 (s, 2H), 1.92 (s, 6H), 1.06 (s, 9H).

[0166] 4.6.2. N-methoxy-N-methylbicyclo[l.l.l]pentane-l-carboxamide

[0167] To a mixture of bicyclo [1.1.1 ]pentane-l -carboxylic acid (14.5 g, 129 mmol, 1.00 eq.), N,O- dimethylhydroxylamine hydrochloride (18.9 g, 193 mmol, 1.50 eq.) and HATU (73.7 g, 193 mmol, 1.50 eq.) in DCM (150 mL) was added dropwise DIPEA (66.8 g, 517 mmol, 4.00 eq.) at 25 ~ 30 °C under N2. The mixture was stirred at 25 °C for 12 hrs. The reaction mixture was diluted with dichloromethane (300 mL) and washed with aq. HC1 (1.00 M, 300 mL), sat. NaHCOs (50.0 mL x 2) and brine (200 mL), dried over Na2SC>4 (25.0 g), fdtered and concentrated to give N-methoxy-N-methylbicyclo[l.l. l]pentane-l- carboxamide (15.4 g, 75.8% yield, 98.8% purity) as yellow oil. MS (ESI) m / z = 156, [M+H]+). 'H-NMR: (400 MHz, CDCh) 8 3.64 (s, 3H), 3.14 (s, 3H), 2.42 (s, 1H), 2.11 (s, 6H). TSRI 2255.1PC / CIB0907P 18350.026WO1

[0168] 4.6.3. 3-fluoro-N-methoxy-N-methylbicyclo[l.l.l]pentane-l-carboxamide

[0169] A mixture of 3-fluoro- bicyclofl. l.l]pentane-l-carboxylic acid (3.35 g, 25.7 mmol, 1.00 eg.), N,O-dimethylhydroxylamine hydrochloride (3.77 g, 38.6 mmol, 1.50 eg.) and HATU (14.6 g, 38.6 mmol, 1.50 eg.) was in DCM (30 mL). DIPEA (13.3 g, 102 mmol, 4.00 eg.) was added dropwise at 25 ~ 30 °C under N2. The mixture was stirred at 25 °C for 12 hrs. The reaction mixture was diluted with dichloromethane (30.0 mL) and washed with aqueous HC1 (1.00 M, 30.0 mL), saturated aqueous NaHCOs (2 x 20.0 mL) and brine (20.0 mL), dried over Na2SC>4 (5.00 g), filtered and concentrated to give 3-fluoro-N-methoxy-N-methylbicyclo[l. l. l]pentane-l-carboxamide (3.25 g, 71.3% yield, 97.9% purity) as a yellow oil. MS (ESI) m / z = 174, [M+H]+). ’H-NMR: (400 MHz, CDCh) 8 3.66 (s, 3H), 3.20 (s, 3H), 2.39 (s, 6H).

[0170] N-methoxy-N,3-dimethylbicyclo[l.l.l]pentane-l-carboxamide and N,3-dimethoxy-N- methylbicyclo[l.l.l]pentane-l-carboxamide was also prepared according to the above procedure.

[0171] 4.6.4. (A)-4-ethyl-8-fluoro-4-hydroxy-ll-(3-(hydroxymethyl)bicyclo[l.l.l]pentan-l-yl)-9- methyl-LH-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4 / f,12 7)-dione

[0172] Step 1. To a solution of 3-fluoro-4-methylaniline (10.0 g, 80.0 mmol) and TEA (24.24 g, 240.0 mmol) in DCM (100 mL) was added AC2O 16.32 g, 160.0 mmol) at 0 °C. The resulting mixture was warmed to room temperature overnight. It was diluted with dichloromethane (100 mL), washed with brine (100 mL x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The residue was TSRI 2255.1PC / CIB0907P 18350.026WO1 triturated with ethyl acetate / petroleum ether (v / v = 2 mL / 40 mL) to give N-(3-fluoro-4-methylphenyl)- acetamide (14.0 g) as a crude product which was used to next step directly. LC-MS: m / z: 168.4 [M+H]+.

[0173] Step 2. A mixture of N-(3-fluoro-4-methylphenyl)acetamide (5.0 g, 30.0 mmol) and NBS (6.40 g, 36.0 mmol) in acetonitrile (100 mL) was stirred at 40°C for 2 h. The reaction mixture was diluted with water (100 mL) and extracted with ethyl acetate (50 mL x 3). The combined organic layers were washed with saturated NaHCO3 (30 mL x 5), brine (30 mL x 3), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to give N-(2-bromo-5-fluoro-4-methylphenyl)acetamide (5.4 g, 73% yield) as a colorless oil. LC-MS: m / z: 246.3 [M+H]+.

[0174] Step 3. To a solution of N-(2-bromo-5-fluoro-4-methylphenyl)acetamide (3.0 g, 12.2 mmol) in anhydrous THF (80 mL) was added n-BuLi (2.5 M in hexane) (12.2 mL, 30.50 mmol) dropwise at -78 °C and stirred at -78 °C for 1 h. Then a solution of 3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo- [l. l. l]pentane-l-carbaldehyde (4.88 g, 13.41 mmol) in anhydrous THF (10 mL) was added to above reaction mixture. The resulting mixture was warmed to room temperature for 2 h. The reaction mixture was poured into saturated NFLC1 (100 mL), extracted with ethyl acetate (100 mL x 3). The combined organic layers were washed with brine (100 mL x 3), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo The residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 10 to 1 / 4) to give N-(2-((3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo- [L L l]pentan-l-yl)(hydroxy)methyl)-5-fluoro-4-methylphenyl)acetamide (4.0 g, 62% yield) as a white solid. LC-MS: m / z: 532.3 [M+H]+.

[0175] Step 4. To a solution ofN-(2-((3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l.l. l]pentan-l- yl)(hydroxy)methyl)-5-fluoro-4-methylphenyl)acetamide (4.0 g, 7.53 mmol) in DCM (80 mL) was added Dess-Martin periodinane (6.39 g, 15.06 mmol) in portions at 0 °C and warmed to room temperature for 2 h. The precipitate was removed by filtration through the Celite. The filtrate was washed with saturated NaHCO3 (30 mL x 3), brine (30 mL x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 50 to 1 / 20) to give N-(2-(3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l.l. l]pentane-l-carbonyl)-5- fhioro-4-methylphenyl)acetamide (2.4 g, 60% yield) as a yellow solid. ’H-NMR (400 MHz, CD3C1): 5 11.70 (s, 1H), 8.48 (d, J = 12.8 Hz, 1H), 7.94 (d, J = 8.4 Hz, 1H), 7.67-7.65 (m, 4H), 7.44-7.37 (m, 6H), 3.73 (s, 2H), 2.27 (s, 3H), 2.21 (s, 3H), 2.18 (s, 6H), 1.08 (s, 9H).

[0176] Step 5. A solution ofN-(2-(3-(((tert-butyldiphenylsilyl)oxy)methyl)-bicyclo[l. l.l]pentane-l- carbonyl)-5-fluoro-4-methylphenyl)acetamide (2.4 g, 4.54 mmol) in 6 N HCl / THF / EtOH (v / v / v = 72 mL / 36 mL / 36 mL) was stirred at 100 °C for 6 h. The solution was removed by reduced pressure. The aqueous phase was adjusted to pH = 7~8 with saturated NaHCO3 and extracted with ethyl acetate (50 mL x 3). The combined organic layers were washed with brine (30 mL x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The resulting residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 5 to 1 / 1) to give (2-amino-4-fhioro-5-methylphenyl)(3- (hydroxymethyl)bicyclo[l. l.l]pentan-l-yl)methanone (1.0 g, 88% yield) as a white solid. LC-MS: m / z: 250.2 [M+H]+. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0177] Step 5. A mixture of (2-amino-4-fluoro-5-methylphenyl)(3-(hydroxymethyl)bicyclo[l.l. l]pentan- l-yl)methanone (400 mg, 1.61 mmol), (S)-4-ethyl-4-hydroxy-7,8-dihydro-lH-pyrano[3,4-f]indolizine- 3,6,10(4H)-trione (423 mg, 1.61 mmol) and pyridinium 4 -toluene sulfonate (445 mg, 1.77 mmol) in anhydrous toluene (40 mL) was stirred at 120 °C for 6 h. The reaction mixture was concentrated in vacuo. The resulted residue was triturated with methanol / water (v / v = 20 mL / 5 mL) to give (S)-4-ethyl-8-fluoro- 4-hydroxy-l l-(3-(hydroxymethyl)bicyclo[l .1. l]pentan-l-yl)-9-methyl-lH-pyrano[3',4':6,7]indolizino- [l,2-b]quinoline-3,14(4H,12H)-dione (320 mg, 42% yield) as a brown solid.1H-NMR (400 MHz, DMSO- d6): 5 8.38 (d, J = 8.4 Hz, 1H), 7.88 (d, J = 10.8 Hz, 1H), 7.30 (s, 1H), 6.51 (br, 1H), 5.43 (s, 2H), 5.42 (s, 2H), 4.69 (br, 1H), 3.56 (s, 2H), 2.53 (s, 3H), 2.48 (s, 6H), 1.90-1.83 (m, 2H), 0.87 (t, J = 7.2 Hz, 3H). LC-MS: m / z: 477.0 [M+H]+.

[0178] 4.6.5. (S)-4-ethyl-8,9-difluoro-4-hydroxy-ll-(3-(hydroxymethyl)bicyclo[l.l.l]pentan-l-yl)-

[0179] IH-pyrano [3',4' : 6,7] indolizino [1,2-b] quinolin e-3,14(4H,12H)-dione

[0180] Step 1. A solution of 2-bromo-4,5-difluoroaniline (5 g, 24.04 mmol) in DCM (60 mL) was cooled to 0°C. Acetyl anhydride (2.7 g, 26.44 mmol) was added to the mixture and stirred at 45 °C under nitrogen atmosphere overnight. The mixture was washed with water. The aqueous layer was extracted with EtOAc(20mL*3). The combined organic layer was dried with Na2SC>4 and filtered. The filtrate was concentrated to give N-(2-bromo-4,5-difluorophenyl)acetamide (5.8 g, 97% yield) as white solid. LCMS: m / z: 249.9 [M+l]+.

[0181] Step 2. A solution of N-(2-bromo-4,5-difluorophenyl)acetamide (3 g, 12.00 mmol) in THF (60 mL) was stirred in -78 °C for 10 minutes, and was added n-BuLi (14.4 mL, 36.00 mmol) and stirred for 1 hour, A solution of 3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l.l. l]pentane-l-carbaldehyde (4.81 g, 13.20 mmol) in anhydrous THF (10 mL) was added to the mixture. It was warmed to room temperature for 2 h. The reaction mixture was poured into saturated NH4CI (200 mL) and extracted with ethyl acetate (200 mL x 3). The combined organic layers were washed with brine (200 mL x 3), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 10 to 1 / 4) to give N-(2-((3-(((tert- TSRI 2255.1PC / CIB0907P 18350.026WO1 butyldiphenylsilyl)oxy)methyl)bicyclo[l .1. l]pentan-l-yl)(hydroxy)methyl)-4,5-difluorophenyl)acetamide (2.4 g, 37% yield) white solid. LCMS: m / z: 535.8 [M+H]+.

[0182] Step 3. To a solution ofN-(2-((3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l.l. l]pentan-l- yl)(hydroxy)methyl)-4,5-difluorophenyl)acetamide (2.4 g, 4.48 mmol) in DCM (80 mb) was added Dess- Martin periodinane (3.8 g, 8.96 mmol) in portions at 0 °C and the mixture was warmed to room temperature for 2 h. The precipitate was removed by fdtration through the Celite. The filtrate was washed with saturated NaHCOs (5=80 mb x 3), brine (80 mb x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The resulting residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 50 to 1 / 20) to give N-(2-(3-(((tert- butyldiphenylsilyl)oxy)methyl)bicyclo[l .1. l]pentane-l-carbonyl)-4,5-difluorophenyl)acetamide (1.8 g, 75% yield) as a yellow solid. ’H-NMR (400 MHz, DMSO-6): 5 10.82 (s, 1H), 7.60-7.62 (m, 5H), 7.42- 7.48 (m, 7H), 3.70 (s, 2H), 2.08-2.09 (m, 9H), 0.99-1.02 (m, 9H).

[0183] Step 4. A solution ofN-(2-(3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l. l.l]pentane-l- carbonyl)-4,5-difluorophenyl)acetamide (1.8 g, 3.37 mmol) in 6 N HCl / THF / EtOH (v / v / v = 72 mL / 36 mL / 36 mL) was stirred at 100 °C for 6 h. The solution was concentrated under reduced pressure. The remaining aqueous phase was adjusted to pH = 7~8 with saturated NaHCOs, extracted with ethyl acetate (50 mL x 3). The combined organic layers were washed with brine (30 mL x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The resulting residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 5 to 1 / 1) to give (2-amino-4,5- difluorophenyl)(3-(hydroxymethyl)bicyclo[l. l.l]pentan-l-yl)methanone (670 mg, 79% yield) as a yellow solid. LC-MS: m / z: 254.2 [M+H]+.

[0184] Step 5. A mixture of (2-amino-4,5-difluorophenyl)(3-(hydroxymethyl)bicyclo[l. l.l]pentan-l- yl)methanone (400 mg, 1.58 mmol), (.S')-4-cthyl-4-hydroxy-7.8-dihydro- l / / -pyrano|3.4- / ]indolizinc- 3,6,10(427)-trione (416 mg, 1.58 mmol) and pyridinium 4 -toluene sulfonate (437 mg, 1.74 mmol) in anhydrous toluene (40 mL) was stirred at 120 °C for 6 h. The reaction mixture was concentrated in vacuo. The resulting residue was triturated with methanol / water (v / v = 20 mL / 5 mL) to give (S)-4-ethyl-8,9- difluoro-4-hydroxy-l l-(3-(hydroxymethyl)bicyclo[l.l. l]pentan-l-yl)-lH-pyrano[3',4':6,7]indolizino[l,2- b]quinoline-3,14(4H,12H)-dione (500 mg, 66% yield) as a grey solid. 'H-NMR (400 MHz, DMSO-de): 5 8.01-8.11 (m, 3H), 7.32 (s, 1H), 6.55 (s, 1H), 5.53(s, 2H), 5.44 (s, 2H), 4.67 (t, J= 5.6 Hz, 1H), 3.53 (d, J = 5.2 Hz, 2H), 2.39 (d, J= 2.4Hz, 6H), 1.83-1.90 (m, 2H), 0.87 (t, J= 7.2 Hz, 3H). LC-MS: m / z: 481.0 [M+H]+. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0185] 4.6.6. (S)-4-ethyl-8-fluoro-4-hydroxy-ll-(3-(hydroxymethyl)bicyclo[l.l.l]pentan-l-yl)-9- methoxy-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H,12H)-dione

[0186] Step 1. To a solution of 3-fluoro-4-methoxyaniline (5.0 g, 35.43 mmol) and in DCM (20 mL) was added Br2 (11.32 g, 70.85 mmol) at -15 °C. The resulting mixture was warmed to room temperature overnight. It was diluted with dichloromethane (100 mL), washed with brine (100 mL x 2), dried over anhydrous sodium sulfate, fdtered and concentrated in vacuo. The resulting residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 10 to 1 / 4) to give 2-bromo-5-fluoro-4- methoxyaniline (5.3 g, 74% yield) as a brown solid. LC-MS: m / z: 221.9 [M+H]+.

[0187] Step 2. A solution of 2-bromo-5-fluoro-4-methoxyaniline (5.3 g, 24.17 mmol) in DCM (50 mL) was added AC2O (2.7 g, 26.59 mmol) at 0 °C. The resulting mixture was stirred at 45°C temperature overnight. The reaction mixture was diluted with dichloromethane (100 mL), washed with brine (100 mL x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 4 to 1 / 2) to give N-(2-bromo-5- fhioro-4-methoxyphenyl)acetamide (6.0 g, 95% yield) as a brown solid. LC-MS: m / z: 261.9 [M+H]+.

[0188] Step 3. To a solution ofN-(2-bromo-5-fhioro-4-methoxyphenyl)acetamide (1.66 g, 6.33mmol) in anhydrous THF (80 mL) was added n-BuLi (2.5 M in hexane) (7.6 mL, 19.00 mmol) dropwise at -78 °C and stirred at -78 °C for 1 h. 3-((( / c / 7-biityldiphcnylsilyl)oxy)mcthyl)bicyclo| I . I . I |pcntanc- l - carbaldehyde (2.54 g, 6.97 mmol) in anhydrous THF (10 mL) was added into the reaction mixture. It was warmed to room temperature for 2 h. The reaction mixture was poured into saturated NH4CI (100 mL) and extracted with ethyl acetate (100 mL x 3). The combined organic layers were washed with brine (100 mL x 3), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 10 to 1 / 4) to give N-(2- ((3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[ 1. 1. l]pentan- l-yl)(hydroxy)methyl)-5-fluoro-4- methoxyphenyl)acetamide (1.26 g, 36% yield) as a yellow solid. LC-MS: m / z: 549.3 [M+H]+.

[0189] Step 4. To a solution ofN-(2-((3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l.l. l]pentan-l- yl)(hydroxy)methyl)-5-fluoro-4-methoxyphenyl)acetamide (1.62 g, 2.97 mmol) in DCM (80 mL) was added Dess-Martin periodinane (2.52 g, 5.93 mmol) in portions at 0 °C and warmed to room temperature TSRI 2255.1PC / CIB0907P 18350.026WO1 for 2 h. The precipitate was removed by filtration through the Celite. The filtrate was washed with saturated NaHCOs (30 mL x 3), brine (30 mL x 2), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 50 to 1 / 20) to give N-(2-(3-(((tert- butyldiphenylsilyl)oxy)methyl)bicyclo[l .1. l]pentane-l-carbonyl)-5-fluoro-4-methoxyphenyl)acetamide (470 mg, 60% yield) as a yellow solid. LC-MS: m / z: 546.3 [M+H]+.

[0190] Step 5. A solution ofN-(2-(3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l. l.l]pentane-l- carbonyl)-5-fluoro-4-methoxyphenyl)acetamide (800 g, 1.47 mmol) in 6 N HCl / THF / EtOH (v / v / v = 20 mL / 10 mL / 10 mL) was stirred at 100 °C for 6 h. The solution was concentrated by reduced pressure and was adjusted to pH = 7~8 with saturated NaHCOs and extracted with ethyl acetate (50 mL x 3). The combined organic layers were washed with brine (30 mL x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 5 to 1 / 1) to give (2-amino-4-fluoro-5-methoxyphenyl)(3- (hydroxymethyl)bicyclo[l. l.l]pentan-l-yl)methanone (300 g, 77% yield) as a yellow solid. LC-MS: m / z: 266.2 [M+H]+.

[0191] Step 6. A mixture of (2-amino-4-fluoro-5-methoxyphenyl)(3-(hydroxymethyl)bicyclo- [l. l. l]pentan-l-yl)methanone (350 mg, 1.32 mmol), (.S')-4-cthyl-4-hydroxy-7.8-dihydro- l / / -pyrano|3.4- / ]indolizine-3,6,10(427)-trione (347 mg, 1.32 mmol) and pyridinium 4-toluenesulfonate (365 mg, 1.45 mmol) in anhydrous toluene (40 mL) was stirred at 120 °C for 6 h. The reaction mixture was concentrated in vacuo. The resulted residue was triturated with methanol / water (v / v = 20 mL / 5 mL) to give (S)-4-ethyl- 8-fluoro-4-hydroxy- 11 -(3 -(hydroxymethyl)bicyclo [1.1.1 ]pentan- 1 -yl)-9-methoxy-lH- pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H,12H)-dione (500 mg, 77% yield) as a yellow solid. ’H-NMR (400 MHz, DMSO-de): 5 7.98 (d, J= 12.04 Hz, 1H), 7.82 (d, J= 9.2 Hz, 1H), 7.27 (s, 1H), 6.51 (br, 1H), 5.43 (s, 2H), 5.42 (s, 2H), 4.71 (br, 1H), 4.08 (s, 3H), 3.56 (s, 2H), 2.48 (s, 6H), 1.90-1.82 (m, 2H), 0.87 (t, J= 7.2 Hz, 3H). LC-MS: m / z: 492.9 [M+H]+.

[0192] 4.6.7. (S)-7-ethyl-7-hydroxy-14-(3-(hydroxymethyl)bicyclo[l.l.l]pentan-l-yl)-7H-

[0193] [1,3] dioxolo[4,5-g]pyrano[3',4':6,7]indolizino[l,2-b]quinoline-8,ll(10H,13H)-dione

[0194] The synthetic scheme used to prepare this compound is shown in FIG. 1. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0195] Step 1. A solution of 5-bromobenzo[d][l,3]dioxole (6 g, 29.85 mmol) in acetyl anhydride (72 mb) was cooled to 0°C, then added HNOs (18 mL). The mixture was warmed to room temperature and stirred under nitrogen atmosphere overnight. The mixture was poured into ice water, washed with NaHCOsl 1 OO L). extracted with ethyl acetate (100mL*3). The combined organic phase was dried with Na2SC>4, fdtered, and concentrated in vacuo. The resulting residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 10 to 1 / 4) to give 5-bromo-6-nitrobenzo[d][l,3]dioxole (5.8 g, 94% yield) as brown solid.

[0196] Step 2. To a mixture of 5-bromo-6-nitrobenzo[d][l,3]dioxole (5.8 g, 23.58 mmol) in EtOH (80 mL) and NH4CI (20 mL), was added Le (3.95 g, 70.73 mmol) and heated to 60°C stirred overnight under nitrogen atmosphere. Saturated ammonium chloride solution (100 mL) was added to the mixture, and extracted with ethyl acetate(100mL*3). The combined organic layers were dried with Na2SC>4 and filtered. The filtrate was concentrated and purified by silica gel column chromatography (THL / PE=20%) to give 6- bromobenzo[d][l,3]dioxol-5-amine (4.4 g, 86% yield) as brown solid. LC-MS: m / z: 217.9 [M+H]+.

[0197] Step 3. To a mixture of 6-bromobenzo[d][l,3]dioxol-5-amine (5.4 g, 25.07 mmol) in DCM (100 mL) was added AC2O (2.82 g, 27.58 mmol) at 0 °C. The resulting mixture was warmed to room temperature overnight. The reaction mixture was diluted with dichloromethane (100 mL), washed with brine (100 mL x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The resulted residue was purified by silica gel column chromatography (THL / PE=20%) to give N-(6- bromobenzo[d][l,3]dioxol-5-yl)acetamide (6.0 g, 93% yield) as white solid. LC-MS: m / z: 260.0 [M+H]+.

[0198] Step 4. To a solution of N-(6-bromobenzo[d][l,3]dioxol-5-yl)acetamide (6.0 g, 23.25 mmol) in anhydrous THE (200 mL) was added n-BuLi (2.5 M in hexane) (28.9 mL, 69.75 mmol) dropwise at -78 °C and stirred at -78 °C for 1 h. Then a solution of 3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo- [l. l. l]pentane-l-carbaldehyde (9.32 g, 25.57 mmol) in anhydrous THF (10 mL) was added into above reaction mixture. It was warmed to room temperature for 2 h. The reaction mixture was poured into saturated NH4CI (200 mL), extracted with ethyl acetate (200 mL x 3). The combined organic layers were washed with brine (200 mL x 3), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 10 to 1 / 4) to give N-(6-((3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l. l. l]pentan-l-yl)(hydroxy)methyl)- benzo[d][l,3]dioxol-5-yl)acetamide (3.0 g, 24% yield) as white solid, and N-(4-((3-(((tert- butyldiphenylsilyl)oxy)methyl)bicyclo[ 1.1.1 ]pentan- 1 -yl)(hydroxy)methyl)benzo [d] [ 1 ,3] dioxol-5 - yl)acetamide (4.0 g, 32% yield) as a white solid. Both with LC-MS: m / z: 544.2 [M+H]+.

[0199] Step 5. To a solution ofN-(6-((3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l.l. l]pentan-l- yl)(hydroxy)methyl)benzo[d][l,3]dioxol-5-yl)acetamide (3.0 g, 5.52 mmol) in DCM (30 mL) was added Dess-Martin periodinane (4.68 g, 11.03 mmol) in portions at 0 °C and warmed to room temperature for 2 h. The precipitate was removed by filtration through the Celite. The filtrate was washed with saturated NaHCOs (30 mL x 3), brine (30 mL x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 50 to 1 / 20) to give N-(6-(3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l. l. l]pentane-l- TSRI 2255.1PC / CIB0907P 18350.026WO1 carbonyl)benzo[d][l,3]dioxol-5-yl)acetamide (1.2 g, 40% yield) as a yellow solid. LC-MS: m / z: 542.3 [M+H]+.

[0200] Step 6. A solution ofN-(6-(3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l. l.l]pentane-l- carbonyl)benzo[d][l,3]dioxol-5-yl)acetamide (1.2 g, 2.22 mmol) in 6 N HCl / THF / EtOH (v / v / v = 20 mL / 10 mL / 10 mb) was stirred at 100 °C for 6 h. The solution was concentrated under reduced pressure. The aqueous phase was adjusted to pH = 7~8 with saturated NaHCOs, extracted with ethyl acetate (50 mb x 3). The combined organic layers were washed with brine (30 mb x 2), dried over anhydrous sodium sulfate, fdtered, and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 5 to 1 / 1) to give (6-aminobenzo[d][l,3]dioxol-5-yl)(3- (hydroxymethyl)bicyclo[l. l.l]pentan-l-yl)methanone (550 mg, 95% yield) as a yellow solid. LC-MS: m / z: 262.3 [M+H]+.

[0201] Step 7. A mixture of (6-aminobenzo[d][l,3]dioxol-5-yl)(3-(hydroxymethyl)bicyclo[l.l. l]pentan- l-yl)methanone (550 mg, 2.11 mmol), (.S')-4-cthyl-4-hydroxy-7.8-dihydro- l / / -pyrano|3.4- / ]indolizinc- 3,6, 10(427)-trione (555 mg, 2.11 mmol) and pyridinium 4 -toluene sulfonate (582 mg, 2.32 mmol) in anhydrous toluene (40 mb) was stirred at 120 °C for 6 h. The reaction mixture was concentrated in vacuo. The resulted residue was triturated with methanol / water (v / v = 20 mL / 5 mb) to give (S)-7-ethyl-7- hydroxy- 14-(3 -(hydroxymethyl)bicyclo [1.1. 1 ]pentan- 1 -yl) -7H- [1,3] dioxolo [4,5- g]pyrano[3',4':6,7]indolizino[l,2-b]quinoline-8,l l(10H,13H)-dione (500 mg, 49% yield) as a yellow solid. ’H-NMR (400 MHz, DMSO-de): 5 7.72(s, 1H), 7.51 (s, 1H), 7.23 (s, 1H), 7.49 (s, 1H), 6.29 (s, 2H), 5.42 (s, 2H), 5.37 (s, 2H), 4.68 (t, J= 5.6 Hz, 1H), 3.53 (d, J= 5.6 Hz, 1H), 2.42 (s, 6H), 1.84-1.88 (m, 2H), 0.87 (t, J= 7.2 Hz, 3H). LC-MS: m / z: 489.0 [M+H]+.

[0202] Similarly, (S)-13-ethyl-13-hydroxy-6-(3-(hydroxymethyl)bicyclo[l.l.l]pentan-l-yl)-7H- [l,3]dioxolo[4,5-h]pyrano[3',4':6,7]indolizino[l,2-b]quinoline-9,12(10H,13H)-dione was prepared from N-(4-((3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[l .1. l]pentan-l- yl)(hydroxy)methyl)benzo[d]-[l,3]dioxol-5-yl)acetamide. ’H-NMR (400 MHz, DMSO-de): 5 7.79 (d, J = 8.8 Hz, 1H), 7.66 (d, J= 8.8 Hz, 1H), 7.25 (s, 1H), 6.50 (br, 1H), 6.32 (s, 2H), 5.42 (s, 2H), 5.41(s, 2H), 4.60 (br, 1H), 3.51(s, 2H), 2.40 (s, 6H), 1.90-1.83 (m, 2H), 0.87 (t, J = 7.2 Hz, 3H). LC-MS: m / z: 489.0 [M+H]+.

[0203] TSRI 2255.1PC / CIB0907P 18350.026WO1

[0204] 4.6.8. (S)-9-amino-ll-(bicyclo[l.l.l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-l,12-dihydro-

[0205] 14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione

[0206] Step 1. 5-bromo-2,4-difluoroaniline (25.0 g, 120 mmol, 1.00 eq.) was added into AC2O (75.0 mL, 3.00 V) by batches at 40 °C under N2. The mixture was stirred at 60 °C for 1 hr. The mixture was quenched with sat. Na2COs at 25 ~ 30 °C to adjust pH ~ 9. The mixture was filtered and the cake was washed with H2O (100 mL). The filtrate was extracted with EA (100 mL) and H2O (100 ml). The organic phase was dried with anhydrous Na2SC>4, filtered and concentrated to give N-(5-bromo-2,4- difluorophenyljacetamide (27.2 g, 90.5% yield, 99%+ purity) as a white solid. ’H-NMR (400 MHz, CDCk): 8 8.59 (t, J= 8.0 Hz, 1H), 7.29 (s, 1H), 6.95 (dd, J= 8.0, 10.4 Hz, 1H), 2.23 (s, 3H)

[0207] Step 2. A mixture of N-(5-bromo-2,4-difluorophenyl)acetamide (27.0 g, 107 mmol, 1.29 eq.) in THF (200 mL) at 25 °C under N2 was cooled to -60 °C and w-BuLi (2.50 M, 222 mmol, 89.1 mL, 2.66 eq.) was added dropwise at -60 °C A solution ofN-methoxy-N-methylbicyclo[l. l. l]pentane-l- carboxamide (13.0 g, 83.7 mmol, 1.00 eq.) in THF (200 mL) was added dropwise at -60 °C. The mixture was stirred at -60 ~ 0 °C for 2 hrs. LC-MS showed the starting material was consumed completely. Sat. NH4CI (200 mL) and MTBE (200 mL) were added dropwise at -60 °C. Then the reaction mixture was warmed to 25 °C and stirred for 10 min, and extracted with MTBE (250 mL). The combined organic solution was washed with brine (100 mL x 2), dried over Na2SC>4, filtered, and concentrated to give a residue. The residue was purified by column chromatography (SiC>2, PE / EA = 100 / 1 - 3 / 1) and the spot (TLC: PE / EA = 2 / 1, Rf (Pi) = 0.60) was collected. The eluent was concentrated to give N-(5- (bicyclo[L Ll]pentane-l-carbonyl)-2,4-difluorophenyl)acetamide (13.7 g, 48.6% yield, 78.9% purity) as light-yellow oil. MS (ESI) m / z = 266, [M+H]+. ’H-NMR: (400 MHz, CDCh) 8 8.71 (t, J= 8.0 Hz, 1H), 6.93 - 6.83 (m, 1H), 2.24 (s, 6H), 2.13 (s, 3H), 2.04 (s, 1H). TSRI 2255.1PC / CIB0907P 18350.026WO1

[0208] Step 3. A mixture ofN-(5-(bicyclo[l.l. l]pentane-l-carbonyl)-2,4-difluorophenyl)acetamide (13.7 g, 51.6 mmol, 1.00 eq), K2CO3(9.28 g, 67.1 mmol, 1.30 eq), and PMBNH2(9.21 g, 67.1 mmol, 1.30 eq) in toluene (150 mL) was stirred at 110 °C for 12 hrs. The reaction mixture was poured into water (100 mb), extracted with MTBE (250 mL). The combined organic solution was washed with sat. brine (100 mL x 2), dried over Na2SC>4 (10.0 g), fdtered and concentrated under reduced pressure to remove the solvent to give N-(5-(bicyclo[l . 1. l]pentane-l-carbonyl)-2-fhioro-4-((4-methoxybenzyl)amino)- phenyl)acetamide (22.5 g, 43.5% yield, 38.2% purity) as light-yellow oil. MS (ESI) m / z = 383, [M+H]+. ’H-NMR: (400 MHz, CDC13) 3 9.31 (s, 1H), 9.16 (d, J= 9.2 Hz, 2H), 8.14 - 8.10 (m, 1H), 7.24 - 7.20 (m, 3H), 7.10-7.14 (m, 3H), 6.37 -6.34 (m, 1H), 4.29 (d, J= 5.6 Hz, 2H), 2.55 (s, 1H), 2.36 (s, 6H), 2.20 (s, 3H).

[0209] Step 4. A mixture ofN-(5-(bicyclo[l.l. l]pentane-l-carbonyl)-2-fluoro-4-((4- methoxybenzyl)amino)phenyl)acetamide (10.2 g, 26.6 mmol, 1.00 eq.) and anisole (14.4 g, 133 mmol, 5.00 eq) in TLA (40.0 mL) was stirred at 25 °C for 2 hrs. The reaction was quenched by addition of EA (100 mL) and Na2CO3 / H2O (25.0 g / 300 mL) and the pH was adjusted to 8 ~ 9 at 25 °C. The aqueous phase was extracted again with EA (100 mL). The organic phases were combined, washed with brine (100 mL), dried over Na2SC>4 (5.00 g), and concentrated under vacuum. The crude product was triturated with PE (50.0 mL) at 25 °C for 10 min to give N-(4-amino-5-(bicyclo[l.l. l]pentane-l-carbonyl)-2- fluorophenyljacetamide (2.95 g, 38.2% yield, 90.8% purity), as a yellow solid. MS (ESI) m / z = 263, [M+H]+. ’H-NMR: (400 MHz, CDC13) 3 9.13 (d, J= 9.2 Hz, 1H), 7.14 (s, 1H), 6.37 (d, J= 12.8 Hz, 2H), 2.56 (s, 1H), 2.37 (s, 6H), 2.22 (s, 3H).

[0210] Step 5. A mixture ofN-(4-amino-5-(bicyclo[l.l. l]pentane-l-carbonyl)-2-fluorophenyl)acetamide (2.60 g, 9.91 mmol, 1.00 eq), (S)-4-ethyl-4-hydroxy-7,8-dihydro-lH-pyrano[3,4-f]indolizine-3,6,10(4H)- trione (2.61 g, 9.91 mmol, 1.00 eq) and TsOH (853 mg, 4.96 mmol, 0.50 eq) in toluene (80.0 mL) at 25 °C under N2was stirred at 110 °C for 6 hrs. The reaction was quenched by addition of toluene (100 mL) and Na2CO3 / H2O (2.50 g / 100 mL) to adjust pH ~ 8 at 25 °C. The mixture was filter and the cake was washed with H2O (50.0 mL) under reduce pressure to give (S)-N-(l l-(bicyclo[l.l.l]pentan-l-yl)-4-ethyl- 8-fluoro-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9- yl)acetamide (2.51 g, 44.6% yield, 86.4% purity) as a gray solid. MS (ESI) m / z = 490, [M+H]+. ’H-NMR: (400 MHz, DMSO) 3 10.17 (s, 1H), 9.49 (d, J= 8.8 Hz, 1H), 7.93 (d, J= 12.4 Hz, 1H), 7.27 (s, 1H), 5.41 (s, 2H), 5.36 (d, J= 3.2 Hz, 2H), 2.77 (s, 1H), 2.61 (s, 6H), 2.23 (s, 3H), 1.89 - 1.82 (m, 2H), 0.87 (t, J= 7.2 Hz, 3H).

[0211] Step 6. (S)-N-( 1 l-(bicyclo[l .1. l]pentan- l-yl)-4-ethyl-8-fluoro-4-hydroxy-3, 14-dioxo-3,4, 12,14- tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)acetamide (2.50 g, 5.11 mmol, 1.00 eq.) was added to HC1 (6 M in water, 6.94 mL, 8.16 eq.) at 25 °C under N2. The mixture was stirred at 80 °C for 4 hrs. The mixture was cooled to 25 °C, then quenched by addition of Na2CO3 / H2O (7.50 g / 100 mL) to adjust pH~8 at 25 °C. The mixture was filtered and washed with H2O (50.0 mL) The solid was freeze- dried to give (S)-9-amino-l l-(bicyclo[l.l.l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-l,12-dihydro-14H- pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione (1.80 g, 76.6% yield, 97.3% purity) as a TSRI 2255.1PC / CIB0907P 18350.026WO1 yellow solid. MS (ESI) m / z = 448, [M+H]+. ’H-NMR: (400 MHz, DMSO) 3 7.73 - 7.68 (m, 2H), 7.19 (s, 1H), 5.40 (s, 2H), 5.34 (s, 2H), 2.76 (s, 1H), 2.59 (s, 6H), 1.88 - 1.81 (m, 2H), 0.86 (t, J= 7.2 Hz, 3H).

[0212] The following compounds were prepared similarly:

[0213] (S)-9-amino-4-ethyl-8-fluoro-ll-(3-fluorobicyclo[l.l.l]pentan-l-yl)-4-hydroxy-l,12-dihydro- 14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione: MS (ESI) m / z = 466, [M+H]+. 'H- NMR: (400 MHz, DMSO-d6) 3 7.75 (d, J= 12.0 Hz, 1H), 7.56 (d, J= 9.6 Hz, 1H), 7.19 (s, 1H), 5.40 (s, 2H), 5.34 (s, 2H), 2.87 (d, J= 2.4 Hz, 6H), 1.90 - 1.79 (m, 2H), 0.86 (t, J= 7.2 Hz, 3H).

[0214] (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-ll-(3-methylbicyclo[l.l.l]pentan-l-yl)-l,12- dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione: MS (ESI) m / z = 462.2 [M+l]+. ’H-NMR: (400 MHz, DMSO-d6) 5 7.72 (d, J= 12.4 Hz, 1 H), 7.66 (d, J= 10.0 Hz, 1 H), 7.18 (s, 1 H), 6.12 (s, 2 H), 5.40 - 5.33 (m, 4 H), 2.44 (s, 6 H), 1.86 - 1.82 (m, 2 H), 1.32 (s, 3 H), 0.86 (t, J= 7.6 Hz, 3 H).

[0215] (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-ll-(3-methoxybicyclo[l.l.l]pentan-l-yl)-l,12- dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione: MS (ESI) m / z = 478.3 [M+23]+. ’H-NMR: (400 MHz, DMSO) 5 7.73 (d, J= 12.4 Hz, 1H), 7.60 (d, J= 9.8 Hz, 1H), 7.19 (s, 1H), 6.46 (s, 1H), 6.13 (s, 2H), 5.40 (s, 2H), 5.33 (s, 2H), 3.36 (s, 3H), 2.64 (s, 6H), 1.90 - 1.79 (m, 2H), 0.86 (t, J = 7.4 Hz, 3H).

[0216] 4.6.9. (S)-14-(bicyclo[l.l.l]pentan-l-yl)-7-ethyl-7-hydroxy-10,13-dihydro-llH- [1,3] dioxolo[4,5-g]pyrano[3',4':6,7]indolizino[l,2-b]quinoline-8,ll(7H)-dione

[0217] Step 1. 5-bromobenzo[d][l,3]dioxole (9.50 g, 47.2 mmol, 1.00 eq.) was added to THF (100 mL) at 25 °C under N2. Then the reaction mixture was cooled to -65 °C and w-BuLi (17.9 mL, 2.50 M, 44.9 mmol, 0.95 eq.) was added dropwise at -65 ~ -60 °C over a period of 20 min. The mixture was stirred at -65 °C for 40 mins. A solution ofN-methoxy-N-methylbicyclo[l.l. l]pentane-l-carboxamide (5.50 g, 35.4 mmol, 0.75 eq.) in THF (100 mL) was added dropwise at -60 °C for 30 mins and the mixture was stirred at -65 °C for 2 hrs. Sat. NH4CI (150 mL) was added dropwise at -60 °C, and the reaction mixture TSRI 2255.1PC / CIB0907P 18350.026WO1 was warmed to 25 °C and stirred for 10 min, and extracted with EA (2 x 200 mL). The combined organic layers was washed with brine (50.0 mL), dried over Na2SC>4 (10.0 g), fdtered and concentrated to give a residue. The residue was purified by column chromatography (SiCE, PE / EA = 50 / 1) to give benzo[d][l,3]dioxol-5-yl(bicyclo[l. l.l]pentan-l-yl)methanone (6.73 g, 61.5% yield, 93.5% purity) as a light-yellow solid. MS (ESI) m / z = 217, [M+H]+. ’H-NMR: (400 MHz, CDC13) 3 7.66 (dd, J= 1.6, 8.0 Hz, 1H), 7.46 (d, J= 1.6 Hz, 1H), 6.84 (d, J= 8.4 Hz, 1H), 6.03 (s, 2H), 2.55 (s, 1H), 2.30 (s, 6H).

[0218] Step 2. To a solution of benzo[d][l,3]dioxol-5-yl(bicyclo[l. l. l]pentan-l-yl)methanone (6.72 g, 31.0 mmol, 1.00 eq.) in AC2O (40.0 mL) was added Cu(NOs)2 (3.50 g, 18.6 mmol, 0.600 eq.) by batches at 0 °C under N2. The mixture was stirred at 0 °C for 2 hrs. It was poured into sat.NaHCCh (200 mL) and extracted with EA (200 mL x 2). The combined organic layers were washed with brine (50.0 mL), dried over Na2SC>4 (20.0 g), filtered and concentrated. The residue was purified by column chromatography (SiC>2, PE / EA = 20 / 1) to give bicyclofl. l. l]pentan-l-yl(6-nitrobenzo[d][l,3]dioxol-5-yl)methanone (4.18 g, 39.3% yield, 76.4% purity), as a light-yellow solid. MS (ESI) m / z = 262, [M+H]+. ’H-NMR: (400 MHz, CDCh) 3 7.60 (s, 1H), 6.64 (s, 1H), 6.19 (s, 2H), 2.50 (s, 2H), 2.07 (s, 6H).

[0219] Step 3. To a solution of bicyclofl. l. l]pentan-l-yl(6-nitrobenzo[d][l,3]dioxol-5-yl)methanone (4.00 g, 15.3 mmol, 1.00 eq.) and NH4CI (4.10 g, 76.5 mmol, 5.00 eq.) in EtOH (40.0 mL) and H2O (40.0 mL) was added Fe (4.28 g, 76.5 mmol, 5.00 eq.) in batches at 40 °C. The mixture was stirred at 60 °C for 2 hrs. With a Brinell funnel, the filter paper was covered with diatomaceous earth, and the unreacted Fe was removed through filtration. The filtrate was concentrated under reduced pressure. The crude was stirred with H2O (100 mL) and extracted with EA (500 mL). The combined organic layers were washed with brine (50.0 mL), dried over Na2SO4 (10.0 g), filtered and concentrated under reduced pressure to give (6-aminobenzo[d][l,3]dioxol-5-yl)(bicyclo[l.l. l]pentan-l-yl)methanone (3.12 g, 85. 1% yield, 96.6% purity) as a light-yellow solid. MS (ESI) m / z = 232, [M+H]+. ’H-NMR: (400 MHz, CDCh) 3 7.39 (s, 1H), 6.48 (brs, 2H), 6.14 (s, 1H), 5.91 (s, 2H), 2.55 (s, 2H), 2.29 (s, 6H).

[0220] Step 4. A mixture of (6-aminobenzo[d][l,3]dioxol-5-yl)(bicyclo[l.l.l]pentan-l-yl)methanone (3.10 g, 13.4 mmol, 1.00 eq.), (S)-4-ethyl-4-hydroxy-7,8-dihydro-lH-pyrano[3,4-f]indolizine-3,6,10(4H)- trione (3.71 g, 14.0 mmol, 1.05 eq.) and TsOH (1.15 g, 6.70 mmol, 0.500 eq.) was added to toluene (120 mL) at 25 °C under N2. It was stirred at 110 °C for 2 hrs. The reaction mixture was filtered, and the cake was washed with H2O (50.0 mL). The crude product was triturated with saturated NaHCCh / DCM (5:2, 280 mL) and dried under reduced pressure to give (S)-14-(bicyclo[l. l.l]pentan-l-yl)-7-ethyl-7-hydroxy- 10, 13 -dihydro- 1 lH-[l,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolizino[l,2-b]quinoline-8,l l(7H)-dione (1.53 g, 23.8% yield, 95.9% purity) as a light-yellow solid. MS (ESI) m / z = 459, [M+H]+. 'H-NMR: (400 MHz, DMSO-d6) 3 7.77 (s, 1H), 7.51 (s, 1H), 7.23 (s, 1H), 6.50 (s, 1H), 6.29 (d, J= 0.8 Hz, 2H), 5.41 (d, J = 17.2 Hz, 1H), 2.74 (s, 1H), 2.59 (s, 6H), 1.89 - 1.82 (m, 2H), 0.87 (t, J= 7.2 Hz, 3H). TSRI 2255.1PC / CIB0907P 18350.026WO1

[0221] 4.6.10. (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-ll-(3-methoxybicyclo[l.l.l]pentan-l-yl)-14- thioxo-12,14-dihydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-3(4H)-one

[0222] Step 1. To a solution of (S)-4-ethyl-4-hydroxy-7,8-dihydro-lH-pyrano[3,4-f]indolizine- 3,6,10(4H)-trione (5.00 g, 18.9 mmol, 1.00 eq) in DCM (50.0 mL) were added imidazole (6.47 g, 94.9 mmol, 5.00 eq) and added dropwise TESCI (11.4 g, 75.9 mmol, 4.00 eq) at 0 °C. After addition, the mixture was stirred at this temperature for 10 minutes, and then N, N-dimethylpyridin-4-amine (2.32 g, 18.9 mmol, 1.00 eq) was added 0 °C. The resulting mixture was stirred at 0 °C for 3 hrs. The reaction mixture was quenched by addition water (100 mL) at 25 °C and extracted with DCM (100 mL x 2), dried over Na2SO4, filtered and concentrated under reduced pressure to give a residue. The crude was purified by column chromatography (SiO2, PE / EA = 10 / 1 to 1 / 1) to give (S)-4-ethyl-4,6-bis((triethylsilyl)oxy)- l,8-dihydro-10H-pyrano[3,4-f]indolizine-3,10(4H)-dione (1.90 g, 18.9% yield, 93.5% purity) was obtained as black-brown oil. MS (ESI) m / z = 492.2 [M+H]+.

[0223] Step 2. To a solution of (S)-4-ethyl-4,6-bis((triethylsilyl)oxy)-l,8-dihydro-10H-pyrano[3,4- f]indolizine-3,10(4H)-dione (1.90 g, 3.86 mmol, 1.00 eq.) in toluene (20.0 mL) was added Lawesson reagent (1.56 g, 3.86 mmol, 1.00 eq). The mixture was stirred at 125 °C for 5 hrs., filtered and concentrated under reduced pressure to give a residue. The residue was purified by column chromatography (SiO2, PE / EA = 20 / 1 to 3 / 1) to give (S)-4-ethyl-10-thioxo-4-((triethylsilyl)oxy)-4,7,8,10- tetrahydro-lH-pyrano[3,4-f]indolizine-3, 6-dione (700 mg, 28.2% yield, 79.3% purity) was obtained as black-brown oil. MS (ESI) m / z = 508.2 [M+H]+.

[0224] Step 3. To a solution of (S)-4-ethyl-10-thioxo-4-((triethylsilyl)oxy)-4,7,8,10-tetrahydro-lH- pyrano[3,4-f]indolizine-3, 6-dione (1.70 g, 3.35 mmol, 1.00 eq.) in THF (20.0 mL) was added TEA.3HF (2.48 g, 15.4 mmol, 4.60 eq) at 0 °C. The mixture was stirred at 25 °C for 12 hrs. The reaction mixture was quenched by addition water (50.0 mL) at 25°C and extracted with EA (100 mL x 2), dried over Na2SO4, filtered and concentrated under reduced pressure to give a residue. The residue was purified by column chromatography (SiO2, PE / EA = 10 / 1 to 3 / 1) to give (S)-4-ethyl-4-hydroxy-10-thioxo-4,7,8,10- tetrahydro-lH-pyrano[3,4-f]indolizine-3, 6-dione (700 mg, 74.8% yield, 94.7% purity) as yellow solid. MS (ESI) m / z = 280.0 [M+H]+. ’H-NMR: (400 MHz, DMSO-d6) 5 7.26 (s, 1H), 5.85 - 5.81 (m, 1H), 5.47 - 5.43 (m, 1H,), 4.42 - 4.37 (m, 2H), 2.99 - 2.89 (m, 2H), 1.81 (q, J = 7.6 Hz, 2H), 0.79 (t, J = 7.6 Hz, 3H). TSRI 2255.1PC / CIB0907P 18350.026WO1

[0225] Step 4. To a solution ofN-(4-amino-2-fhioro-5-(3-methoxybicyclo[l.l.l]pentane-l- carbonyl)phenyl)acetamide (1.33 g, 4.55 mmol, 1.00 eq.) in toluene (20.0 mL) were added (S)-4-ethyl-4- hydroxy-10-thioxo-4,7,8,10-tetrahydro-lH-pyrano[3,4-f]indolizine-3,6-dione (1.27 g, 4.55 mmol, 1.00 eq.) and 4-methylbenzenesulfonic acid (783 mg, 4.55 mmol, 1.00 eq.). The mixture was stirred at 110 °C for 6 hrs and then cooled to room temperature. Sat. NaHCO3 aqueous solution was added to the reaction mixture to adjust pH to ~8. The solid was filtered and washed with water to give (S)-N-(4-ethyl-8-fluoro- 4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3-oxo-14-thioxo-3,4,12,14-tetrahydro-lH- pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)acetamide(1.90 g, 53.0% yield, 68.0% purity) as blackbrown solid. MS (ESI) m / z = 536.4 [M+H]+.

[0226] Step 5. (S)-N-(4-ethyl-8-fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3-oxo-14- thioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)acetamide (1.90 g, 3.55 mmol, 1.00 eq) was added into aq. HC1 (19.0 mL, 6.00 M, 1.00 eq). The mixture was stirred at 80 °C for 4 hrs and cooled to room temperature. Sat. NaHCO3 aqueous solution was added to adjust pH to ~8. The precipitate was filtered, washed with water, and dried to give (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-l 1- (3-methoxybicyclo[l.l.l]pentan-l-yl)-14-thioxo-12,14-dihydro-lH-pyrano[3',4':6,7]indolizino[l,2- b]quinolin-3(4H)-one (1.52 g, 82.6% yield, 95.2% purity) as a black-brown solid. MS (ESI) m / z = 494.1 [M+H]+. ’H-NMR: (400 MHz, DMSO-d6) 57.81 - 7.72 (m, 1H), 7.67 (s, 1H), 7.62 (d, J = 9.6 Hz 1H,), 5.92 - 5.88 (m, 1H), 5.54 - 5.46 (m, 3H), 3.37 (s, 3H), 2.66 (s, 6H), 1.90 - 1.86 (m, 2H), 0.85 (t, J = 7.6 Hz, 3H).

[0227] 4.6.11. (S)-ll-(3-(2-aminoethoxy)bicyclo[l.l.l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-9- methyl-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione

[0228] The synthetic scheme used to prepare this compound is disclosed in FIG. 2. The general procedure to synthesize V-82-1: TSRI 2255.1PC / CIB0907P 18350.026WO1

[0229] To a solution of V-82-0 (25 g, 146.9 mmol) in DCM (400 mL) was added DMF (3 drops) and stirred at 0°C for 10 mins. The oxalyl chloride (22.4 g, 176.3 mmol) was dropwise added to the reaction mixture over 10 mins, and the mixture was stirred at r.t. for 1 hour under nitrogen atmosphere. The mixture was evaporated in vacuo to give the crude product.

[0230] The general procedure to synthesize V-82-2:

[0231] To a solution of N,O-dimethylhydroxylamine (17.2 g, 176.3 mmol) in DCM (300 mL) was added TEA (44.5 g, 440.7 mmol) and stirred at 0 °C for 10 mins. The V-82-1 (27.7 g, 146.9 mmol) dissolved in 200 mL dry DCM was dropwise added to the reaction mixture over 10 mins. After stirring for 2 hours under nitrogen atmosphere, the mixture was evaporated in vacuo to give crude product. Further purification with chromatography (THF: PE = 1:9) gives title product V-82-2 (25 g, 80% yield) as a white solid.

[0232] LC-MS m / z: 214.4 [M+ H]+.

[0233] The general procedure to synthesize V-82-3:

[0234] A solution of V-82-2 (25 g, 117.2 mmol) in THF (400 mL) was stirred at 0 °C for 10 mins.

[0235] Phenylmagnesium bromide (18 mL, Imol / L) was dropwise added to the reaction over 10 mins, and the reaction micture was stirred at r.t. overnight under nitrogen atmosphere. The mixture was extracted with EtOAc. The organic phase was evaporated in vacuo to give crude product. Further purification with chromatography (THF: PE = 1:4) gives title product V-82-3 (14.5 g, 54% yield) as a white solid. LC-MS m / z: 231.3 [M+ H]+.

[0236] The general procedure to synthesize V-82-4:

[0237] V-82-3 V-82-4 TSRI 2255.1PC / CIB0907P 18350.026WO1

[0238] To a solution of V-82-3 (35 g, 152.2 mmol) in DCM (300 mL) was added TFA (26 g, 228.3 mmol) and m-CPBA (65.7 g, 380.5 mmol). The reaction was stirred at r.t. overnight. After the reaction was completed, the mixture was washed with sodium thiosulfate. The organic phase was washed with saturated sodium bicarbonate solution and evaporated in vacuo to give the crude product. Further purification with chromatography (THF: PE = 1:9) gives title product V-82-4 (30 g, 80% yield) as a white solid. LC-MS m / z: 247.3 [M+ H]+.

[0239] The general procedure to synthesize V-82-5:

[0240] To a solution of V-82-4 (15 g, 60.9 mmol) was added MeOH / HCl (4 N, 150 mL) and the mixture was stirred at 50 °C for 4 hours. After the reaction was completed, the mixture was evaporated in vacuo to give crude product. Further purification with chromatography (THF: PE = 1:4) gives title product V-82-5 (7.5 g, 87% yield) as a light-yellow oil.

[0241] The general procedure to synthesize V-89-2a:

[0242] Br^^OTf

[0243] DIEA, toluene, 80 °C, 2 d

[0244] V-89-1a V-89-2a

[0245] To a solution of V-89-la (10.00 g, 38.91 mmol) in toluene (200mL) was added V-82-5 (5.53 g, 38.91 mmol) and TEA (7.87 g, 77.81 mmol). The mixture was stirred for 2 d at 80 °C under nitrogen atmosphere. After consumption of the starting material (monitored by LCMS), the mixture was diluted with water (200 mL) and extracted with EtOAc (80 mL x 3). The combined organic layers were washed with brine (60 mL x 2), dried over sodium sulfate and concentrated to dryness. The residue was purified by column chromatography on silica gel (petrol ether / EtOAc = 2 / 1) to give V-89-2a (8.00 g, 83 % yield) as light-yellow oil.

[0246] The general procedure to synthesize V-89-3: TSRI 2255.1PC / CIB0907P 18350.026WO1

[0247] To a solution of V-89-2a (3.80 g, 15.25 mmol) in DMF (50 mL) was added (PMB)2NH (3.93 g, 15.25 mmol) and K2CO3 (4.22 g, 30.51 mmol). The mixture was stirred overnight at 90 °C under nitrogen atmosphere. After consumption of the starting material (monitored by LCMS), the mixture was diluted with water (50 mL) and extracted with EtOAc (30 mL x 3). The combined organic layers were washed with brine (40 mL x 2), dried over sodium sulfate and concentrated to dryness. The residue was purified by column chromatography on silica gel (petrol ether / EtOAc = 1 / 1) to give V-89-3 (2.60 g, 40 % yield) as a light-yellow solid. LC-MS m / z: 426.3 [M+l]+.

[0248] The general procedure to synthesize V-89-6:

[0249] V-89-3 V-89-6

[0250] To a solution of V-89-3 (2.60 g, 6.11 mmol) in THF (50 mL) was added DIBA1-H (30.55 mL, 30.55 mmol) at 0 °C. The mixture was then warmed to room temperature and stirred for 2 h under nitrogen atmosphere. After consumption of the starting material (monitored by LCMS), The mixture was diluted with water (60 mL). The solid was fdtered, and the fdtrate was extracted with ethyl acetate (40 mL x 3). The combined organic layers were washed with brine (50 mL x 2), dried over sodium sulfate, and concentrated to dryness. The residue was purified by column chromatography on silica gel (petrol ether / EtOAc = 3 / 1) to give V-89-6 (2.20 g, 91 % yield) as colorless oil. LC-MS m / z: 398.1 [M+l]+.

[0251] The general procedure to synthesize V-89-7:

[0252] V-89-6 V-89-7

[0253] To a solution of V-89-6 (2.20 g, 5.53 mmol) in CH2CI2 (20 mL) was added DMP (3.52 g, 8.30 mmol). The mixture was stirred overnight at room temperature under nitrogen atmosphere. After consumption of the starting material (monitored by LCMS), the mixture was diluted with water (60 mL) and extracted with CH2C12 (40 mL x 3). The combined organic layers were washed with brine (30 mL x 2), dried over sodium sulfate and concentrated to dryness. The residue was purified by column chromatography on silica gel (petrol ether / EtOAc = 1 / 1) to give V-89-7 (1.80 g, 82 % yield) as colorless oil. LC-MS m / z: 396.1 [M+l]+.

[0254] The general procedure to synthesize V-9-2: TSRI 2255.1PC / CIB0907P 18350.026WO1

[0255] To a solution of V-9-1 (25.00 g, 199.78 mmol) in AcOH (20 mL) was added AC2O (34.17 g, 199.78 mmol). The mixture was stirred for 2 h at 90 °C under nitrogen atmosphere. After consumption of the starting material (monitored by LCMS), the mixture was diluted with water (300 mL) and extracted with EtOAc (200 mL x 3). The combined organic layers were washed with brine (90 mL x 2), dried over sodium sulfate and concentrated to dryness. The residue was purified by column chromatography on silica gel (petrol ether / EtOAc = 10 / 1) to give V-9-2 (30.0 g, 90 % yield) as a light-yellow solid. LC-MS m / z: 168.4 [M+l]+.

[0256] The general procedure to synthesize V-9-3:

[0257] V-9-2 V-9-3

[0258] To a solution of V-9-2 (30.00 g, 179.45 mmol) in DMF (500 mL) was added NBS (31.94 g, 179.45 mmol). The mixture was stirred overnight at room temperature. After consumption of the starting material (monitored by TLC), the mixture was diluted with water (300 mL) and extracted with EtOAc (200 mL x 3). The combined organic layers were washed with brine (90 mL x 2), dried over sodium sulfate and concentrated to dryness. The residue was purified by column chromatography on silica gel (petrol ether / EtOAc = 10 / 1) to give V-9-3 (25.00 g, 57 % yield) as a white solid. LC-MS m / z: 246.2 [M+l]+.

[0259] The general procedure to synthesize V-9-4:

[0260] To a solution of V-9-3 (3.60 g, 14.63 mmol) in THF (100 mL) was added n-BuLi (18 mL, 43.89 mmol) at -78 °C. After stirring for 1 h, V-89-7 (1.74 g, 4.39 mmol) was added. The mixture was warmed to 0 °C and stirred at 0 °C for 2 h under nitrogen atmosphere. After consumption of the starting material (monitored by LCMS), the mixture was diluted with ice-cooled saturated aqueous solution of NH4CI (80 mL) and extracted with EtOAc (70 mL x 3). The combined organic layers were washed with brine (80 mL x 2), dried over sodium sulfate and concentrated to dryness. The residue was purified by column chromatography on silica gel (petrol ether / EtOAc = 1 / 2) to give V-9-4 ( 1.80 g, 22 % yield) as a lightyellow solid. LC-MS m / z: 563.2 [M+l]+. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0261] The general procedure to synthesize V-9-5:

[0262] To a solution of V-9-4 (2.20 g, 3.91 mmol) in CH2C12 (60 mL) was added DMP (2.49 g, 0.01 mmol). The mixture was stirred overnight at room temperature under nitrogen atmosphere. After consumption of the starting material (monitored by LCMS), the mixture was diluted with water (60 mL) and extracted with CH2CI2 (50 mL x 3). The combined organic layers were washed with brine (40 mL x 2), dried over sodium sulfate and concentrated to dryness. The residue was purified by column chromatography on silica gel (petrol ether / EtOAc = 1 / 1) to give V-9-5 (1.60 g, 73 % yield) as colorless oil. LC-MS m / z: 561.2 [M+l]+.

[0263] The general procedure to synthesize V-9-6:

[0264] To a solution of V-9-5 (500 mg, 0.89 mmol) in EtOH (20 mL) was added HC1 (4 mL, 26.75 mmol). The mixture was stirred for 3 h at 100 °C under nitrogen atmosphere. After consumption of the starting material (monitored by LCMS), the mixture was diluted with water (50 mL) and extracted with EtOAc (40 mL x 3). The combined organic layers were washed with brine (30 mL x 2), dried over sodium sulfate and concentrated to dryness. The residue was purified by column chromatography on silica gel (petrol ether / EtOAc = 1 / 1) to give V-9-6 (450 mg, 97 % yield) as a light-yellow solid. LC-MS m / z: 519.2 [M+l]+.

[0265] The general procedure to synthesize V-9-7: TSRI 2255.1PC / CIB0907P 18350.026WO1

[0266] To a solution of V-9-6 (450 mg, 0.87 mmol) in toluene (20 mL) was added CAS 110351-94-5 (228 mg, 0.87 mmol) and PPTS (218 mg, 0.87 mmol). The mixture was stirred for 5 h at 120 °C under nitrogen atmosphere. After consumption of the starting material (monitored by LCMS), the mixture was cooled to room temperature, diluted with water (30 mL) and extracted with EtOAc (30 mL x 3). The combined organic layers were washed with brine (20 mL x 2), dried over sodium sulfate and concentrated to dryness. The residue was purified by column chromatography on silica gel (McOH / CfLCL = 1 / 10) to give V-9-7 (500 mg, 77 % yield) as a white solid. LC-MS m / z: 746.0 [M+l]+.

[0267] 4.6.12. (S)-ll-(3-(2-aminoethoxy)bicyclo[l.l.l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-9- methyl-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione

[0268] To a solution of V-9-7 (450 mg, 0.60 mmol) in chlorobenzene (20 mL) was added 2, 3, 4,5,6- pentafluorobenzenethiol (362 mg, 1.81 mmol) and AIBN (297 mg, 1.81 mmol). The mixture was stirred for 3 h at 80 °C under nitrogen atmosphere. After consumption of the starting material (monitored by LCMS), the mixture was cooled to room temperature, diluted with water (30 mL) and extracted with EtOAc (30 mL x 3). The combined organic layers were washed with brine (20 mL x 2), dried over sodium sulfate and concentrated to dryness. The residue was purified by column chromatography on silica gel (MeOH / CELCh = 1 / 10) to give (S)-l l-(3-(2-aminoethoxy)bicyclo[l .1. l]pentan-l-yl)-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 (160 mg, 52 % yield) as a white solid. ’H-NMR (400 MHz, DMSO-tL) 5 8.32 (d, J= 8.0 Hz, 1H), 7.98 (br, 3H), 7.91 (d, J= 10.4 Hz, 1H), 7.32 (s, 1H ), 5.43 (s, 4H ), 3.79 (t, J= 5.2 Hz, 2H ), 3.08 (q, J= 5.6 Hz, 2H ), 2.76 (s, 6H ), 2.55 (s, 3H), 1.93-1.79 (m, 2H), 0.87 (t, J= 7.6 Hz, 3H). LC-MS m / z: 505.8 [M+l]+.

[0269] 4.6.13. (S)-2-amino-N-(2-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14- tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan- l-yl)oxy)ethyl)acetamide TSRI 2255.1PC / CIB0907P 18350.026WO1

[0270] Step 1: To a solution of (S)-l l-(3-(2-aminoethoxy)bicyclo[l.l.l]pentan-l-yl)-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 (80 mg, 0.16 mmol) in DMF (5 mL) was added 2-((tert-butoxycarbonyl)amino)acetic acid (33 mg, 0.19 mmol), HATU (90 mg, 0.24 mmol) and DIEA (82 mg, 0.63 mmol). The mixture was stirred overnight at room temperature under nitrogen atmosphere. After consumption of the starting material (monitored by LCMS), the mixture was diluted with water (30 mL) and extracted with EtOAc (20 mL x 3). The combined organic layers were washed with brine (30 mL x 2), dried over sodium sulfate and concentrated to dryness. The residue was purified by column chromatography on silica gel (CFLCL / McOH = 10 / 1) to give V-9-8 (60 mg, 57 % yield) as an off-white solid. LC-MS m / z: 663.2 [M+l]+.

[0271] Step 2: V-9-7 (45 mg, 0.07 mmol) was added to HCl / MeOH (1 / 1 v / v, 5 mL). The mixture was stirred at room temperature overnight. After consumption of the starting material (monitored by LCMS), the mixture was concentrated in vacuo. The residue was diluted with EtOAc (2000 mL), washed with saturated aqueous Na2COs (500 mL x 3), dried over sodium sulfate and concentrated in vacuo. The residue was purified by column chromatography on silica gel (petrol ether / EtOAc = 1 / 2) to give the desired product (31 mg, 81% yield) as a white solid. ’H-NMR (400 MHz, DMSO-t / e) 5 8.56 (t, J= 5.6 Hz, 1H ), 8.32 (d, J= 8.0 Hz, 1H), 8.03 (br, 3H), 7.90 (d, J= 10.4 Hz, 1H), 7.31 (s, 1H ), 6.53 (s, 1H ), 5.42 (d, J= 6.8 Hz, 4H), 3.64 (t, J= 5.6 Hz, 2H ), 3.61-3.55 (m, 2H ), 3.45-3.38 (m, 2H ), 2.74 (s, 6H ), 2.55 (s, 3H), 1.93-1.79 (m, 2H), 0.87 (t, J= 7.2 Hz, 3H). LC-MS m / z: 563.3 [M+l]+.

[0272] 4.6.14. (S)-2-amino-N-(((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14- tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan- 1 -yl)methoxy)m ethyl) acet am ide TSRI 2255.1PC / CIB0907P 18350.026WO1

[0273] Step 1: a solution of (.S)-4-cthyl-8-fluoro-4-hydroxy-l l-(3-(hydroxymcthyl)bicyclo| l . l . l |pcntan- l-yl)-9-mcthyl-l / / -pyrano|3'.4':6.7|indolizino| l.2-b|quinolinc-3. 14(4 / / . l2 / / )-dionc (1.0 g, 2.0 mmol) in anhydrous DMF (30 mL) was added (2-((((9 / / -fliiorcn-9-yl)mcthoxy)carbonyl)amino)acctamido)mcthyl acetate 1599440-06-8 (3.68 g, 10.0 mmol) and BFs.Et20 (284 mg, 2.0 mmol). The reaction mixture was stirred at 50 °C for 2 h. The reaction mixture was extracted with ethyl acetate (30 mL x 3). The combined organic layers were washed with brine (30 mL x 3), dried over anhydrous sodium sulfate, fdtered and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (MeOH / DCM = 1 / 50 to 1 / 10) to give (.S)-(9 / / -fluorcn-9-y I (methyl (2-((((3-(4-ethyl-8-fluoro-4-hydroxy-9- methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-l 1- yl)bicyclo[l.l.l]pentan-l-yl)methoxy)methyl)amino)-2-oxoethyl)carbamate (3290-10) (300 mg, 61% yield) as a white solid. LCMS: m / z: 785.3 [M+l]+.

[0274] Step 2: A solution of (.S)-(9 / / -fluorcn-9-yl)mcthyl (2-((((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl- 3,14-dioxo-3,4,12,14-tetrahydro-l / / -pyrano[3',4':6,7]indolizino[l,2-b]quinolin-l 1- yl)bicyclo[l.l.l]pentan-l-yl)methoxy)methyl)amino)-2-oxoethyl)carbamate (3290-10) (300 mg, 0.38 mmol) in THF (3 mL) and diethylamine (1 mL) was stirred at room temperature for 4 h. The reaction mixture was concentrated in vacuo. The resulted residue was purified by Prep-HPLC to give (.S)-2-amino- A-(((3-(4-cthyl-8-fluoro-4-hydroxy-9-mcthyl-3. l4-dioxo-3.4.12. 14-tctrahydro-l H- pyrano [3 426,7] indolizino [ 1 ,2-b]quinolin- 11 -yl)bicyclo[ 1.1.1 ]pentan- 1 -yl)methoxy)methyl)acetamide (10 mg, 5% yield) as a white solid. ’H-NMR (400 MHz, CD3OD): 5 8.35-8.31 (m, 1H), 7.69-7.63 (m, 1H), 7.59-7.56 (m, 1H), 5.59-5.55 (m, 1H), 5.40-5.35 (m, 3H), 4.80 (s, 2H), 3.69 (s, 2H), 3.58 (s, 2H), 2.60 (s, 6H), 2.52 (s, 3H), 1.97-1.94 (m, 2H), 1.00 (t, J= 7.2 Hz, 3H). LCMS: m / z: 563.2 [M+H]+.

[0275] 4.6.15. (S)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-ll-(3-(methylthio)bicyclo[l.l.l]pentan-l- yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione

[0276] The synthetic scheme used to prepare this compound is shown in FIG. 3.

[0277] Synthesis of 596-1: TSRI 2255.1PC / CIB0907P 18350.026WO1

[0278] A solution of 596-0 (5.0 g, 29.4 mmol) in DCM (509 mL) was treated with DMF (2 drops) followed by oxalyl chloride (5.7 mL, 58.8 mmol). The solution was stirred at rt for 2.5 h. The solvent was removed under reduced pressure to give a yellow solid as 596-1.

[0279] Synthesis of 596-2:

[0280] The crude acid chloride 596-1 was re-dissolved in toluene (50 mL) and dimethyl disulfide (13 mL) was added while the solution was protected from light. In a separate flask, 2-pyridinethiol-l-oxide sodium salt (12. 1g, 32.4 mmol) in toluene (50 mL) was heated to 50° C. The solution containing the acid chloride was added dropwise to the 2-pyridinethiol-l-oxide sodium salt solution while being irradiated with a halogen work lamp. Once the addition was complete, the mixture was irradiated for 6 h at 50°C. The reaction was quenched with sat. aq. NaHCO3 (100 mL) and further diluted with H2O (100 mL). The solution was extracted with EtOAc (4 x 80 mL). The combined organics were dried (Na2SO4). After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by column chromatography with PE / EtOAc (10: 1) to give a colorless oil as 596-2 (2.67 g, 67.6%).

[0281] Synthesis of 596-3:

[0282] 596-2 596-3

[0283] A mixture of 596-2 (2.5 g, 14.5 mmol) and LiOH (1.53 g, 36.3 mmol) in THF (50 mL) / H2O (10 mL) was stirred at room temperature for 16 h. The reaction mixture was adjust to pH = 4~5 with 1.0 N aq.HCl, and extracted with EA (3x50 mL). The combined organic phase was washed with brine (100 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to give a white solid as 596-3 (2.1 g, 91.4%).

[0284] Synthesis of 596-4:

[0285] 596-3 596-4 TSRI 2255.1PC / CIB0907P 18350.026WO1

[0286] A solution of 596-3 (2.1 g, 13.3 mmol) in DCM (50 mL) was treated with DMF (2 drops) followed by oxalyl chloride (3.38 g, 26.6 mmol). The solution was stirred at rt for 2.5 h. The solvent was concentrated under reduced pressure to give a yellow solid as 596-4 (2.1 g, 89.8%).

[0287] Synthesis of 596-5:

[0288] 596-4 596-5

[0289] A mixture of 596-4 (2.1 g), N,O-dimethylhydroxylamine (1.95 g, 19.9 mmol), DIPEA (5.14 g, 39.9 mmol) in DCM (50 mL) was stirred at room temperature for 16 h. The mixture was poured into H2O and extracted with ethyl acetate (3x100 mL). The combined organic phase was washed with brine (100 mL), dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by column chromatography with PE / EtOAc (10: 1) to give a yellow solid as 596-5 (2.2 g, 89.6%).

[0290] Synthesis of 596-6: 596-5

[0291] To a solution of N-(2-bromo-5-fluoro-4-methoxyphenyl)acetamide (1.52 g, 5.82 mmol) in THF (80 mL) was added n-BuLi (2.5 M in hexane) (4.36 mL, 10.9 mmol) dropwise at -78 °C and stirred at -78 °C for 1 h. Then a solution of 596-5 (1.0 g, 4.95 mmol) in THF (10 mL) was added into above reaction mixture. The mixture was warmed to room temperature for 2 h. The reaction mixture was poured into saturated NH4CI (100 mL), extracted with ethyl acetate (100 mL x 3). The combined organic layers were washed with brine (100 mL x 3), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulted residue was purified by column chromatography with (EA / PE = 1 / 10 to 1 / 4) to give 596-6 (0.42 g, 26.3% yield) as a yellow solid. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0292] Synthesis of 596-7:

[0293] 596-6 596-7

[0294] A solution of 596-6 (250 mg, 0.77 mmol) in 6 N HC1 / EtOH (v / v = 24 mL / 12 mL) was stirred at 100 °C for 16 h. The solution was removed by reduced pressure. The aqueous phase was adjusted to pH = 7~8 with saturated NaHCOs, extracted with ethyl acetate (50 mL x 3). The combined organic layers were washed with brine (30 mL x 2), dried over anhydrous sodium sulfate, fdtered and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 5 to 1 / 1) to give 596-7 (1.0 g, 88% yield) as a white solid. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by CC. with PE / EtOAc (10: 1) to give a yellow solid as 596-7 (110 mg, 50.6%).

[0295] 4.6.16. (S)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-ll-(3-(methylthio)bicyclo[l.l.l]pentan-l- yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione

[0296] 596-7

[0297] A mixture of 596-7 (140 mg, 0.50 mmol), S (131 mg, 0.50 mmol) and PPTS (125 mg, 0.50 mmol) in toluene (40 mL) was stirred at 110 °C for 16 h. The reaction mixture was concentrated in vacuo. The residue was purified by CC. with DCM / MeOH (10: 1) to give a white solid as (S)-4-ethyl-8-fluoro- 4-hydroxy-9-methoxy-l l-(3-(methylthio)bicyclo[l. l.l]pentan-l-yl)-l,12-dihydro-14H- pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione (105 mg, 41.5%). LCMS: 509.1 [M+H]+. 'H- NMR (400 MHz, DMSO-d6): 5 8.0 (d,lH), 7.7 (d, 1H), 7.27 (s, 1H), 6.51 (s, 1H), 5.5 (s, 2H), 5.42 (s, 2H), 4.1 (s, 3H), 2.75 (s,6H), 2.2 (s, 3H), 1.90-1.82 (m, 2H), 0.87 (t, 3H). TSRI 2255.1PC / CIB0907P 18350.026WO1

[0298] 4.6.17. (S)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-ll-(3-

[0299] (methylsulfonyl)bicyclo[l.l.l]pentan-l-yl)-l,12-dihydro-14H- pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione

[0300] To a solution of (S)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-l l-(3-(methylthio)bicyclo[l.l.l]- pentan- 1 -yl)- 1 , 12-dihydro- 14H-pyrano [3 ',4' : 6,7]indolizino [ 1 ,2-b] quinoline-3 , 14(4H)-dione (60 mg, 0.12 mmol) in DCM (10 mL) was added m-CPBA (73 mg, 0.30 mmol) at 0°C and stirred at room temperature for 16 h. The mixture was poured into H2O, extracted with DCM (3x 20 mL). The combined organic phase was washed with brine (100 mL), dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The residue was purified by CC. with DCM / MeOH (15: 1) to give (S)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy- 11 -(3-(methylsulfonyl)bicyclo[ 1.1. l]pentan- 1 -yl)- 1,12- dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione as a white solid (20 mg, 31.4%). LC-MS: 541.3 [M+H]+. ’H-NMR (400 MHz, DMSO-d6): 5 8.05 (d,lH), 7.7 (d, 1H), 7.27 (s, 1H), 6.51 s, 1H), 5.5 (s, 2H), 5.42 (s, 2H), 4.1 (s, 3H), 3.1 (s, 3H), 3.0 (s, 6H), 1.90-1.82 (m, 2H), 0.87 (t, 3H).

[0301] 4.6.18. (S)-ll-(3-(aminomethyl)bicyclo[l.l.l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-9- methyl-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione

[0302] The synthetic method used to prepare this compound is shown in FIG. 4. The synthesis of methyl 3- (((methylsulfonyl)oxy)methyl)bicyclo[l .1.1] pentane -1 -carboxylate (3553-1):

[0303] A mixture ofmethyl 3-(hydroxymethyl)bicyclo[l.l.l]pentane-l-carboxylate (14.0 g, 40.8 mmol) imidazole (6.7 g, 98.80 mmol) and TBDPSC1 (16.3 g, 59.2 mmol) in DMF (150 mL) was stirred at room temperature overnight. The reaction mixture was diluted with water (500 mL), extracted with ethyl acetate TSRI 2255.1PC / CIB0907P 18350.026W01

[0304] (300 mL x 2). The combined organic layers were washed with bnne (200 mb x 2), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 50 to 1 / 5) to give methyl 3- (((methylsulfonyl)oxy)methyl)bicyclo[l.l. l]pentane-l-carboxylate (3553-1) (15.0 g, 71% yield) as a yellow oil. ’H-NMR (400 MHz, DMSO-6): 5 4.23 (s, 2H), 3.61 (s, 3H), 3.17 (s, 3H), 2.00 (s, 6H).

[0305] The synthesis of methyl 3-((bis(4-methoxybenzyl)amino)methyl)bicyclo[l. l.l] pentane-1- carboxylate (3553-2):

[0306] A mixture ofmethyl 3-(((methylsulfonyl)oxy)methyl)bicyclo[l.l. l]pentane-l-carboxylate (15.0 g, 64.1 mmol), TEA (19.4 g, 192.3 mmol) and (PMB)NH2 (32.9 g, 128.2 mmol) in MeCN (30 mL) was stirred at 60°C for 24 h under N2 atmosphere. After the consumption of the starting material (monitored by LCMS), the reaction mixture was diluted with water (30 mL), and extracted with ethyl acetate (30 mL x 2). The combined organic layers were washed with brine (20 mL x 2), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 50 to 1 / 5) to give methyl 3-((bis(4-methoxybenzyl)amino)- methyl)bicyclo[l.l.l]pentane-l-carboxylate (3553-2) (23.0 g, 92% yield) as a yellow solid. LC-MS: m / z: 396.3 [M+H]+.

[0307] The synthesis of (3-((bis(4-methoxybenzyl)amino)methyl)bicyclo[l.l. l] pentan- l-yl)methanol (3553-3):

[0308] To a solution of 3-((bis(4-methoxybenzyl)amino)methyl)bicyclo[l.l.l]pentane-l-carboxylate (23.0 g, 59.7 mmol) in anhydrous THF (50 mL) was added LiAlFL (2.5 M in THF, 45 mL, 89.6 mmol) dropwise at 0 °C and the resulted mixture was stirred at 0 °C for 2 h. The reaction mixture was diluted with THF (50 mL), and water (4.5 mL) was added dropwise and stirred for 15 min. NaOH (15% wt, 4.5 mL) was then added dropwise and stirred for 15 min. Additional water (4.5 mL) was added dropwise and stirred for 15 min. Finally, the mixture was dried over anhydrous magnesium sulfate, filtered and the filtrate was concentrated in vacuo to give (3-((bis(4-methoxybenzyl)amino)methyl)bicyclo[l.l. l]pentan-l- yl)methanol (3553-3) (17.0 g, 81% yield) as a yellow solid. LC-MS: m / z: 368.4 [M+H]+. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0309] The synthesis of 3-((bis(4-methoxybenzyl)amino)methyl)bicyclo[ 1.1.1] pentane -1-carbaldehyde (3553-4):

[0310] 3553-3 3553-4

[0311] To a solution of (3-((bis(4-methoxybenzyl)amino)methyl)bicyclo[l.l. l]pentan-l-yl)methanol (17.0 g, 46.3 mmol) in DCM (50 mL) was added PCC (30.0 g, 138.0 mmol) in portions at 0 °C and the reaction mixture was stirred at room temperature for 2 h. The precipitate was removed by filtration through Celite. The filtrate was washed with brine (50 mL x 2), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 50 to 1 / 3) to give 3-((bis(4-methoxybenzyl)amino)- methyl)bicyclo[l.l.l]pentane-l-carbaldehyde (3553-4) (9.06 g, 54% yield) as a yellow solid. ’H-NMR (400 MHz, DMSO- e): 5 9.49 (s, 1H), 7.26 (d, J= 8.4 Hz, 4H), 6.89 (d, J= 8.4 Hz, 4H), 3.73 (s, 6H), 3.44 (s, 4H), 2.43 (s, 2H), 1.89 (s, 6H).

[0312] The synthesis ofN-(2-((3-((bis(4-methoxybenzyl)amino)methyl)bicyclo[l.l. l] pentan-1- yl)(hydroxy)methyl)-5-fluoro-4-methylphenyl)acetamide (3553-5):

[0313] To a solution of JV-(2-bromo-5-fluoro-4-methylphenyl)acetamide (3290-2) (12.1 g, 49.4 mmol) in anhydrous THF (40 mL) was added n-BuLi (2.5 M in hexane, 24.7 mL, 49.4 mmol) dropwise at -78 °C and the reaction mixture was stirred at -78 °C for 1 h. Then a solution of 3-((bis(4- methoxybenzyl)amino)methyl)bicyclo[ 1.1.1] pentane- 1-carbaldehyde (9.0 g, 24.7 mmol) in anhydrous THF (10 mL) was added into above reaction mixture. The resulting mixture was stirred at room temperature for 2 h. The reaction mixture was poured into saturated NH4CI (100 mL) and extracted with ethyl acetate (50 mL x 3). The combined organic layers were washed with brine (50 mL x 3), dried over anhydrous sodium sulfate, fdtered and concentrated in vacuo The resulted residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 10 to 1 / 4) to give N-(2-((3-((bis(4- methoxybenzyl)amino)methyl)bicyclo [1.1. 1 ]pentan- 1 -yl)(hydroxy)methyl)-5 -fluoro-4- methylphenyl)acetamide (3553-5) (6.4 g, 49% yield) as a yellow solid. LC-MS: m / z: 533.3 [M+H]+. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0314] The synthesis of N-(2-(3-((bis(4-methoxybenzyl)amino)methyl)bicyclo[ 1.1.1] pentane-1- carbonyl)-5-fluoro-4-methylphenyl)acetamide (3553-6):

[0315] To a solution ofN-(2-((3-((bis(4-methoxybenzyl)amino)methyl)bicyclo[l.l. l] pentan- l-yl)(hydroxy)- methyl)-5-fluoro-4-methylphenyl)acetamide (3553-5) (6.4 g, 12 mmol) in DCM (50 mL) was added Dess- Martin (12. 1 g, 24 mmol) in portions at 0 °C and the reaction mixture was stirred at room temperature for 2 h. The precipitate was removed by fdtration through the Celite. The fdtrate was washed with saturated NaHCOs (30 mL x 3), brine (30 mL x 2), dried over anhydrous sodium sulfate, fdtered and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 50 to 1 / 5) to give N-(2-(3-((bis(4-methoxybenzyl)amino)methyl)-bicyclo[l. l.l]pentane-l- carbonyl)-5-fluoro-4-methylphenyl)acetamide (3553-6) (3.7 g, 55% yield) as a yellow solid. LC-MS: m / z: 531.0 [M+H]+.

[0316] The synthesis of (2-amino-4-fluoro-5-methylphenyl)(3-((bis(4-methoxybenzyl) amino)methyl)bicyclo [1.1.1] pentan- 1 -yl)methanone (3553- 7) :

[0317] A solution ofN-(2-(3-((bis(4-methoxybenzyl)amino)methyl)bicyclo[l. l. l]pentane-l -carbonyl)-5-fluoro- 4-methylphenyl)acetamide (3553-6) (3.7 g, 7 mmol) in 6 N HCl / THF / EtOH (v / v / v = 72 mL / 36 mL / 36 mL) was stirred at 100 °C for 3 h. The solvent was removed under reduced pressure. The aqueous phase was adjusted to pH = 7~8 with saturated NaHCOs and extracted with ethyl acetate (50 mL x 3). The combined organic layers were washed with brine (30 mL x 2), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulting residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 5 to 1 / 1) to give (2-amino-4-fluoro-5-methylphenyl)(3-((bis(4- methoxybenzyljamino) methyljbicyclo [1.1.1] pentan- l-yl)methanone (3553-7) (3.0 g, 88% yield) as a yellow solid. LC-MS: m / z: 489.1 [M+H]+. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0318] The synthesis of (.8)- l l-(3-((bis(4-mcthoxybcnzyl)amino)mcthyl)bicyclo| l . l . l | pentan- l-yl)-4- ethyl-8-fluoro-4-hydroxy-9-methyl-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H,12H) -dione (3553-8):

[0319] A mixture of (2-amino-4-fluoro-5-methylphenyl)(3-((bis(4-methoxybenzyl)amino) methyl)bicyclo [1.1.1] pentan- l-yl)methanone (3553-7) (3.7 g, 7.6 mmol), (5)-4-ethyl-4-hydroxy-7,8- dihydro-l / / -pyrano|3.4- / ]indolizinc-3.6. IO(4 / / )-trionc (2.4 g, 9.1 mmol) and pyridinium 4- toluene sulfonate (3.9 g, 22.8 mmol) in anhydrous toluene (25 mL) was stirred at 120 °C for 5 h. The reaction mixture was concentrated in vacuo. The resulted residue was triturated with methanol / water (20 mL / 5 mL) to give (.8)- 1 l-(3-((bis(4-methoxybenzyl)amino)methyl)bicyclo[ 1.1.1 ]pentan-l-yl)- 4-ethyl-8- fluoro-4-hydroxy-9-methyl- 127-pyrano [3 ',4' : 6,7]indolizino [ 1 ,2-b]quinoline-3 , 14(4 / 2.12 / / )-dionc (3553-8) (5.0 g, 93% yield) as a brown solid. LC-MS: m / z: 716.2 [M+H]+.

[0320] The synthesis of (.8)- 1 1 -(3-(aminomcthyl)bicyclo| I . I . I Ipcntan- 1 -yl)-4-cthyl-8- fluoro-4-hydroxy- 9-methyl- 127-pyrano [3', 4' : 6,7] indolizino [ 1 ,2-b]quinoline-3 , 14(4 / 2.1227)-dione :

[0321] A solution of (S)-l l-(3-((bis(4-methoxybenzyl)amino)methyl)bicyclo[l.l.l] pentan- l-yl)-4-ethyl-8- fluoro-4-hydroxy-9-methyl- IH-pyrano [3 ',4' : 6, 7] indolizino [ 1 ,2-b]quinoline-3 , 14(4H, 12H)-dione (3553-8) (5.0 g, 7 mmol) in chlorobenzene (30 mL) was added AIBN (230 mg, 1.4 mmol) and 2, 3, 4,5,6- pentafluorobenzenethiol (560 mg, 2.8 mmol), the mixture was stirred at 80°C for 3 h. The precipitate was removed by fdtration through the Celite. The fdtrate was washed with brine (30 mL x 2), dried over anhydrous sodium sulfate, fdtered and concentrated in vacuo. The resulting residue was purified by flash chromatography on silica gel (methanol / dichloromethane = 1 / 50 to 1 / 10) to give (S)-l l-(3- (aminomethyl)bicyclo[Ll.l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-lH- pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H,12H)-dione (1.0 g crude, 30% yield) as ayellow solid. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0322] The crude was purified by Prep-HPLC to give (S)-l l-(3-(aminomethyl)bicyclo[l.l.l]pentan-l- yl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline- 3,14(4H)-dione (18.30 mg, 18% yield). ’H-NMR (400 MHz, DMSO-d6): 5 8.34 (d, J = 8.0 Hz, 1H), 8.14 (br, 3H), 7.91 (d, J = 10.4 Hz, 1H), 7.31 (s, 1H), 5.43 (d, J = 6.8 Hz, 4H), 3.10-3.09 (m, 2H), 2.62 (s, 6H), 2.54 (s, 3H), 1.90-1.83 (m, 2H), 0.87 (t, J = 6.8 Hz, 3H). LCMS: m / z: 476.2 [M+l]+.

[0323] 4.6.19. (iS)-JV-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-l / f- pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l-yl)methyl)-2- hydroxyacetamide

[0324] To a solution of A'-(6-((3-(((tcrt-biityldiphcnylsilyl)oxy)mcthyl)bicyclo| I . I . I |pcntan-l- yl)(hydroxy)m 5)- 11 -(3-(aminomethyl)bicyclo[ 1.1.1 ]pentan- 1 -yl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl- l / / -pyrano|3'.4':6.7|indolizino| l.2-b|quinolinc-3.14(4 / / . l2 / / )-dionc (100 mg, 0.21 mmol) in DMF (3 mL) were added glycolic acid (32 mg, 0.42 mmol), TCFH (592 mg, 2.1 mmol) and NMI (344 mg, 4.2 mmol). The reaction mixture was stirred at room temperature for 48 h. The mixture reaction was washed by brine (3 mL x 2) and extracted with ethyl acetate (3 mL x 2). The combined organic layers were dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulted residue was purified by Prep-HPLC to give (.S)- '-((3-(4-cthyl-8-fluoro-4-hydroxy-9-mcthyl-3. l4-dioxo-3.4.12.14-tctrahydro-l / / - pyrano[3', 4':6, 7] indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l-yl)methyl)-2 -hydroxyacetamide (15.18 mg, 13% yield) as a white solid. ’H-NMR (400 MHz, CD3OD): 5 8.35 (d, J= 8.0 Hz, 1H), 7.70 (d, J= 10.8 Hz, 1H), 7.60 (s, 1H), 5.60-5.56 (m, 1H), 5.41-5.36 (m, 3H), 4.06 (s, 2H), 3.54 (s, 2H), 2.57 (s, 6H), 2.53 (s, 3H), 1.97-1.94 (m, 2H), 1.00 (t, J= 7.6 Hz, 3H). LCMS: m / z: 534.1 [M+l]+.

[0325] 4.6.20. (iS)-JV-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-l / f- pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l-yl)methyl)-3- hydroxypropanamide TSRI 2255.1PC / CIB0907P 18350.026WO1

[0326] The synthetic scheme used to prepare this compound is shown in FIG. 5. The synthesis of methyl 3-((tert-butyldiphenylsilyl)oxy)propanoate (5819-2):

[0327] 5819-1 5819-2

[0328] A mixture of methyl 3-hydroxypropanoate (1.0 g, 10.0 mmol), imidazole (2.0 g, 30.0 mmol) and TBDPSCI (3.3 g, 12.0 mmol) in DMF (15 mb) was stirred at room temperature 2 h. The reaction mixture was diluted with water (15 mb), extracted with ethyl acetate (15 mb x 2). The combined organic layers were washed with brine (15 mb x 2), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (ethyl acetate / petroleum ether = 1 / 50 to 1 / 20) to give methyl 3-((tert-butyldiphenylsilyl)oxy)propanoate (5819-2) (2.0 g, 58% yield) as a colorless oil.

[0329] The synthesis of 3-((tert-butyldiphenylsilyl)oxy)propanoic acid (5819-3): H

[0330] 5819-2 5819-3

[0331] A solution of methyl 3-((tert-butyldiphenylsilyl)oxy)propanoate (5819-2) (500 mg, 1.46 mmol) and LiOH (281 mg, 11.70 mmol) in McOH / lTO (10 mL / 5 mb) was stirred at room temperature for 2 h. The reaction mixture was adjusted to pH = 7~8 with HC1 (1.0 M) and extracted with ethyl acetate (10 mb x 3). The combined organic layers were washed with brine (10 mb x 2), dried over anhydrous sodium sulfate, fdtered and concentrated in vacuo to give 3-((tert-butyldiphenylsilyl)oxy)propanoic acid (5819-3) (300 mg, 63% yield) as a white solid. LC-MS: m / z: 327.2[M-H]‘.

[0332] The synthesis of (S)-3-((tert-butyldiphenylsilyl)oxy)- / V-((3-(4-ethyl-8-fluoro-4-hydroxy-9- methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-l 1- yl)bicyclo[l .1. l]pentan-l-yl)methyl)propanamide (5819-4):

[0333] To a solution of 3-((tert-butyldiphenylsilyl)oxy)propanoic acid (5819-3) (100 mg, 0.30 mmol) , (S)-l l-(3- (aminomethyl)bicyclo[ 1. 1. 1 ]pentan- 1 -yl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl- \H- pyrano[3',4':6,7]indolizino[ 1 ,2-b |quinolinc-3. 14(4 / / . ! 2 / / )-dionc (145 mg, 0.30 mmol) and NMI (125 mg, TSRI 2255.1PC / CIB0907P 18350.026WO1

[0334] 1.52 mmol) in DMF (5 mL) was added TCFH (128 mg, 0.46 mmol). The reaction mixture was stirred at room temperature for 2 h. The reaction mixture was diluted with water (10 mL) and extracted with ethyl acetate (10 mL x 3), washed with brine (10 mL x 3), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (methanol / dichloromethane = 1 / 100 to 1 / 10) to give (S)-3-((tert-butyldiphenylsilyl)oxy)-A-((3-(4-ethyl-8- fluoro-4-hydroxy-9-mcthyl-3. l4-dioxo-3.4.12. l4-tctrahydro-l / / -pyrano|3'.4':6.7|indolizino| 1.2- b]quinolin-l l-yl)bicyclo[l.l.l]pentan-l-yl)methyl)propanamide (5819-4) (80 mg, 34% yield) as a white solid.

[0335] 4.6.21. (5)-JV-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo- 3,4,12,14-tetrahydro-

[0336] LH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l- yl)methyl)-3-hydroxypropanamide

[0337] A solution of (S)-3-((tert-butyldiphenylsilyl)oxy)- / V-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3, 14- dioxo-3.4.12. l4-tctrahydro-l / / -pyrano|3'.4':6.7|indolizino| l.2-b|quinolin-l 1 -yl)bicyclo[ 1.1.1 ]pentan-l- yl)methyl)propanamide (5819-4) (80 mg, 0.10 mmol) in THF (3 mL) and pyridine hydrofluoride (1 mL) was stirred at room temperature for 4 h. The reaction mixture was concentrated in vacuo. The resulted residue was purified by Prep-HPLC to give (.S)-A-((3-(4-cthyl-8-fluoro-4-hydroxy-9-mcthyl-3. l4-dioxo- 3.4. 12.14-tctrahydro- l / / -pyrano|3'.4':6.7|indolizino| 1 ,2-b|quinolin- 1 1 -yl)bicyclo| I . I . I Ipcntan- 1 - yl)methyl)-3-hydroxypropanamide (18 mg, 33% yield) as a white solid. ’H-NMR (400 MHz, CD3OD): 5 8.35 (d, J= 8.4 Hz, 1H), 7.69 (d, J= 9.8 Hz, 1H), 7.59 (s, 1H), 5.60-5.56 (m, 1H), 5.41-5.35 (m, 3H), 3.87 (t, J= 6.4 Hz, 2H), 3.48 (s, 2H), 2.57 (s, 6H), 2.52-2.47 (m, 5H), 1.97-1.94 (m, 2H), 1.00 (t, J= 7.2 Hz, 3H). LCMS: m / z: 548.2 [M+H]+.

[0338] TSRI 2255.1PC / CIB0907P 18350.026WO1

[0339] 4.6.22. 2-Hydroxyethyl (S)-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14- tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan- l-yl)methyl)carbamate

[0340] Step 1: A solution ofbis(perfluorophenyl)methanone (152 mg, 0.42 mmol), 2-((tert- butyldimethylsilyl)oxy)ethanol (62 mg, 0.35 mmol) and TEA (106 mg, 1.05 mmol) in DCM (5 mL) was stirred at room temperature for 0.5 h. A-(6-((3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo [1.1.1 ]pentan- l-yl)(hydroxy)m .S)- 1 l-(3-(aminomethyl)bicyclo[l .1.l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-9- methyl-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H,12L / )-dione (100 mg, 0.21 mmol) and TEA (106 mg, 1.05 mmol) in DCM (2 mL) was added into above mixture. The reaction mixture was stirred at room temperature for 4 h. The reaction mixture was washed by brine (5 mL x 2) and extracted with dichloromethane (5 mL x 2). The combined organic layers were dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (methanol / dichloromethane = 1 / 50 to 1 / 10) to give (.S)-2-((tcrt-butyldimcthylsilyl)oxy)cthyl ((3- (4-ethyl-8-fluoro-4-hydroxy-9-methyl-3, 14-dioxo-3,4, 12, 14-tetrahydro- l / / -pyrano|3'.4':6.7|indolizino- [l,2-b]quinolin-l l-yl)bicyclo[l.l.l]pentan-l-yl)methyl)carbamate (70 mg crude, 49% yield) as a yellow solid. LC-MS: m / z: 678.3 [M+H]+.

[0341] Step 2: A solution of (S)-2-((tert-butyldimethylsilyl)oxy)ethyl ((3-(4-ethyl-8-fluoro-4-hydroxy-9- methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-l 1- yl)bicyclo[l.l.l]pentan-l-yl)methyl)carbamate (70 mg, 0.10 mmol) in THE (5 mL) was added HF in pyridine (2 mL), and the reaction mixture was stirred at room temperature for 3 h. The reaction mixture was concentrated in vacuo. The resulted residue was purified by Prep-HPLC to give (S)-2 -hydroxyethyl ((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]- indolizino[l,2-b]quinolin-l l-yl)bicyclo[l.l.l]pentan-l-yl)methyl)carbamate (15.91 mg, 27% yield) as a white solid. ’H-NMR (400 MHz, DMSO-d6): 5 8.36 (d, J = 8.0 Hz, 1H), 7.89 (d, J = 10.8 Hz, 1H), 7.35- 7.30 (m, 2H), 6.51 (s, 1H), 5.43-5.41 (m, 4H), 4.73 (t, J = 5.6 Hz, 1H), 4.01 (t, J = 5.2 Hz, 2H), 3.58-3.56 (m, 2H), 3.25 (d, J = 5.6 Hz, 2H), 2.53 (s, 3H), 2.48 (s, 6H), 1.90-1.83 (m, 2H), 0.87 (t, J = 7.2 Hz, 3H). LCMS: m / z: 564.2 [M+l]+. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0342] 4.6.23. (S)-2-Amino-N-((2-(((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14- tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan- l-yl)methyl)amino)-2-oxoethoxy)methyl)acetamide

[0343] The synthetic scheme used to prepare this compound is shown in FIG. 6.

[0344] Step 1: To a solution of / V-(6-((3-(((tert-butyldiphenylsilyl)oxy)methyl)bicyclo[ 1.1.1] pentan-1- yl)(hydroxy)m S)-l l-(3-(aminomethyl)bicyclo[l.l.l]pentan-l-yl)-4-ethyl-8- fluoro-4-hydroxy-9-methyl- l / / -pyrano|3'.4':6.7|indolizino| l.2-b|quinolinc-3.14(4 / / . l2 / / )-dionc (300 mg, 0.63 mmol) in DMF (3 mL) were added l-(9 / / -fliiorcn-9-yl)-3.6-dioxo-2.9-dioxa-4.7-diazaundccan-l 1-oic acid (483 mg, 1.26 mmol), TCFH (354 mg, 1.26 mmol) and NMI (258 mg, 3.15 mmol). The reaction mixture was stirred at room temperature for 1 h. The reaction mixture was washed by brine (3 mL x 2) and extracted with ethyl acetate (3 mL x 2). The combined organic layers were dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The resulted residue was purified by flash chromatography on silica gel (methanol / dichloromethane = 1 / 50 to 1 / 10) to give (S)-(9H-fhioren-9-yl)methyl (2-(((2-(((3-(4-ethyl-8- fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2- b]quinolin- 11 -yl)bicyclo [1.1.1 ]pentan- 1 -yl)methyl)amino)-2-oxoethoxy)methyl)amino)-2- oxoethyl)carbamate (100 mg, 19% yield) as a yellow solid. LC-MS: m / z: 842.3 [M+H]+.

[0345] Step 2: A mixture of (S)-(9 / / -fhiorcn-9-y I [methyl (2-(((2-(((3-(4-ethyl-8-fluoro-4-hydroxy-9- methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-l 1- yl)bicyclo [1.1.1 ]pentan- 1 -yl)methyl)amino)-2 -oxoethoxy )methyl)amino)-2-oxoethyl)carbamate (100 mg, 0.12 mmol) and diethylamine (0.5 mL) in anhydrous DCM (5 mL) was stirred at room temperature for 2 h. The reaction mixture was concentrated in vacuo. The resulted residue was purified by Prep-HPLC to give (.S)-2-amino-A'-((2-(((3-(4-cthyl-8-fliioro-4-hydroxy-9-mcthyl-3. l4-dioxo-3.4.12.14-tctrahydro-l / / - pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l-yl)methyl)amino)-2- oxoethoxy)methyl)acetamide (10.64 mg, 15% yield) as a white solid. ’H-NMR (400 MHz, DMSO-de): 5 8.88 (s, 1H), 8.36 (d, J= 8.0 Hz, 1H), 8.03-8.00 (m, 1H), 7.88 (d, J= 10.8 Hz, 1H), 7.30 (s, 1H), 6.52 (s, 1H), 5.43-5.41 (m, 4H), 4.68 (s, 3H), 3.95 (s, 2H), 3.39 (d, J= 8.8 Hz, 2H), 3.26 (s, 2H), 2.53 (s, 3H), 2.48 (s, 6H), 1.87-1.82 (m, 2H), 0.87 (t, J= 7.2 Hz, 3H). LC-MS: m / z: 620.2 [M+H]+. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0346] 4.6.24. (S)-N-((S)-4-ethyl-8-fluoro-4-hydroxy-ll-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3,14- dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)-2- hydroxypropanamide

[0347] Step 1. To a solution of methyl (S)-2-hydroxypropanoate (5 g, 48.0 mmol, 1.0 eq.) in DMF (80 mL) at 0 °C was added TBDMS-C1 (10.8 g, 71.7 mmol, 1.5 eq.) and imidazole (11.4 g, 168 mmol, 3.5 eq.), and then stirred at room temperature for 16 hours. The reaction mixture was quenched with H2O (80 mL), and extracted with petroleum ether (100 mL x 3). The combined organic phase was washed with brine (80 mL), dried over anhydrous Na2SC>4, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel (0 to 3 % ethyl acetate in petroleum ether) to give methyl (S)-2-((tert-butyldimethylsilyl)oxy)propanoate (4.7 g, yield 45.0 %) as colorless oil. ’H NMR (400 MHz, CDC13) 54.24 (q, J = 6.8 Hz, 1H), 3.62 (s, 3H), 1.30 (d, J = 6.8 Hz, 3H), 0.78 (s, 9H), -0.03 (s, 3H), -0.10 (s, 3H) ppm.

[0348] Step 2. To a solution of methyl (S)-2-((tert-butyldimethylsilyl)oxy)propanoate (1.0 g, 4.58 mmol, 1.0 eq.) in THF (20 mL) was added the solution of LiOH (0.44 g, 18.4 mmol, 4 eq.) in H2O (10 mL) at 0°C, and then stirred at room temperature for 5 hours. The reaction mixture was quenched with H2O (50 mL), and extracted with Et2O (50 mL x 3). The aqueous layer was acidified with KHSO4 solution (1 mol / L) to pH=5~6, and extracted with EtOAc (50 mL x 6). The combined organic phase was dried over Na2SC>4, filtered and concentrated under reduced pressure to give (S)-9-amino-4-ethyl-8-fluoro-4- hydroxy- 11 -(3 -methoxybicyclo [1.1.1 ]pentan- 1 -yl)- 1 , 12-dihydro- 14H-pyrano [3 ',4' : 6,7]indolizino [ 1 ,2-b] quinoline-3,14(4H)-dione (600 mg, crude), which was in next step directly without further purification. ’HNMR (400 MHz, CDCh) 54.22 (q, J = 6.8 Hz, 1H), 1.31 (d, J = 7.2 Hz, 3H), 0.78 (s, 9H), -0.04 (s, 6H) ppm.

[0349] Step 3. To a solution of (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-l l-(3- methoxybicyclo[l .1. l]pentan-l-yl)-l, 12-dihydro-14H-pyrano[3',4':6,7]indolizino [ 1 ,2-b] quinoline- 3,14(4H)-dione (50 mg, 0.10 mmol, 1.0 eq.) in DMF (1 mL) was added (S)-2-((tert- butyldimethylsilyl)oxy)propanoic acid (110 mg, 0.52 mmol, 5.0 eq.), HOAt (110 mg, 0.84 mmol, 8.0 eq.), HATU (320 mg, 0.84 mmol, 8.0 eq.) and DIEA (54 mg, 0.42 mmol, 4.0 eq.) at room temperature, and then stirred at 40°C for 16 hours. The reaction mixture was purified by prep-HPLC (C18 column, 0-70 % MeCN in water with 0.05 % FA) to give (S)-2-((tert-butyldimethylsilyl)oxy)-N-((S)-4-ethyl-8-fluoro-4- hydroxy-1 l-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3,14-dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7] indolizino[l,2-b]quinolin-9-yl)propanamide (15 mg, yield 22.0 %) as a yellow solid. ESI m / z: 664.3 (M+H)+. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0350] Step 4. To a solution of (S)-2-((tert-butyldimethylsilyl)oxy)-N-((S)-4-ethyl-8-fluoro-4-hydroxy- 11 -(3 -methoxybicyclo [1.1. l]pentan-l-yl)-3,14-dioxo-3,4, 12, 14-tetrahydro-lHpyrano[3',4':6,7] indolizino[l,2-b]quinolin-9-yl)propanamide (13 mg, 20 pmol, 1 eq.) in THF (2 mb) was added a solution of TFA (0.2 mL) in H2O (2 mb) at 0°C, and then stirred at room temperature for 5 hours. The reaction mixture was purified by reverse phase HPLC (C18 column, 10-50 % MeCN in water with 0.01 % FA) to give (S)-N-((S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3,14-dioxo- 3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)-2-hydroxypropanamide (9 mg, yield 80 %) as a yellow solid. ESI m / z: 550.2 (M+H)+. ’H NMR (400 MHz, DMSO-d6) 59.70 (s, 1H), 9.44 (d, J = 8.8 Hz, 1H), 8.06 (d, J = 12.0 Hz, 1H), 7.31 (s, 1H), 6.53 (s, 1H), 6.18 (d, J = 5.6 Hz, 1H), 5.43 (s, 4H), 4.37 - 4.34 (m, 1H), 3.36 (s, 3H), 2.69 (s, 6H), 1.90 - 1.83 (m, 2H), 1.40 (d, J = 6.8 Hz, 3H), 0.87 (t, J = 7.2 Hz, 3H).

[0351] (R)-N-((S)-4-ethyl-8-fluoro-4-hydroxy-ll-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3,14-dioxo- 3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)-2-hydroxypropanamide was prepared according to the same scheme, ESI m / z: 550.0 (M+H)+. ’H NMR (500 MHz, DMSO-d6) 59.70 (s, 1H), 9.44 (d, J = 8.5 Hz, 1H), 8.06 (d, J = 12.1 Hz, 1H), 7.31 (s, 1H), 6.52 (s, 1H), 6.19 (d, J = 5.3 Hz, 1H), 5.43 (s, 4H), 4.40 - 4.32 (m, 1H), 3.36 (s, 3H), 2.69 (s, 6H), 1.95 - 1.78 (m, 2H), 1.40 (d, J = 6.8 Hz, 3H), 0.87 (t, J = 7.4 Hz, 3H).

[0352] 4.6.25. (R)-N-((S)-4-ethyl-8-fluoro-4-hydroxy-ll-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3- oxo-14-thioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9- yl)-2-hydroxypropanamide

[0353] To a solution of (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l- yl)-14-thioxo-12,14-dihydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-3(4H)-one (40 mg, 81 pmol,l eq.) in DMF (1.5 mL) was added (R)-2-((tert-butyldimethylsilyl)oxy)propanoic acid (83 mg, 0.41 mmol, 5 eq.), HATU (250 mg, 0.65 mmol, 8 eq.), HOAT (88 mg, 0.65 mmol, 8 eq.) and DIPEA (42 mg, 0.32 mmol, 4 eq.), and then stirred at 40 °C for 16 hours. LCMS showed that the TBDMS group of the amide product was removed, and the main peak was the expected final target. The reaction mixture was purified by prep-HPLC (C18 column, 0-70 % MeCN in water with 0.05 % TFA) to give (R)-N-((S)-4-ethyl-8- fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3-oxo-14-thioxo-3,4,12,14-tetrahydro-lH- pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)-2-hydroxypropanamide (10 mg, yield 18 %) as yellow solid. ESI m / z: 566.2 (M+H)+. ’HNMR (400 MHz, DMSO-d6) 9.73 (d, J = 2.3 Hz, 1H), 9.47 (d, J = 8.7 Hz, 1H), 8.08 (dd, J = 23.3, 12.1 Hz, 1H), 7.78 (d, J = 3.6 Hz, 1H), 6.77 - 6.50 (m, 1H), 6.19 (d, J = 5.3 TSRI 2255.1PC / CIB0907P 18350.026WO1

[0354] Hz, 1H), 5.93 (d, J = 16.6 Hz, 1H), 5.64 (s, 2H), 5.53 (d, J = 16.5 Hz, 1H), 4.43 - 4.29 (m, 1H), 3.38 (s, 3H), 2.72 (s, 6H), 1.91-1.86 (m, 2H), 1.40 (d, J = 6.8 Hz, 3H), 0.85 (t, J = 7.3 Hz, 3H).

[0355] 4.6.26. (S)-2-amino-N-((S)-4-ethyl-8-fluoro-4-hydroxy-ll-(3-methoxybicyclo[l.l.l]pentan-l- yl)-3,14-dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9- yl)propenamide

[0356] Step 1. To a solution of (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-l l-(3- methoxybicyclo[l.l.l]pentan-l-yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline- 3,14(4H)-dione (50 mg, 0.10 mmol, 1 eq.) in DMF (2 mL) was added (((9H-fluoren-9- yl)methoxy)carbonyl)-L-alanine (0.16 g, 0.52 mmol, 5 eq.), 3H-[l,2,3]triazolo[4,5-b]pyridin-3-ol (0.11 g, 0.84 mmol, 8 eq.), HATU (0.32 g, 0.84 mmol, 8 eq.) and N-ethyl-N-isopropylpropan-2-amine (54 mg, 0.42 mmol, 4 eq.), and then stirred at 40 °C for 16 hours. The reaction mixture was purified by prep- HPLC (C18 column, 0-85% MeCN in water with 0.05 % TFA) to give (9H-fluoren-9-yl)methyl ((S)-l- (((S)-4-ethyl-8-fluoro-4-hydroxy- 11 -(3 -methoxybicyclo [ 1.1. l]pentan-l-yl)-3, 14-dioxo-3,4, 12, 14- tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)amino)-l-oxopropan-2-yl)carbamate (45mg, 55.6% ) as a yellow solid. ESI m / z: 771.0 (M+H)+.

[0357] Step 2. To a solution of (9H-fluoren-9-yl)methyl ((S)-l-(((S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3- methoxybicyclo[l.l.l]pentan-l-yl)-3,14-dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2- b]quinolin-9-yl)amino)-l-oxopropan-2-yl)carbamate (45 mg, 58 pmol, 1 eq.) in DMF (2 mL) was added diethylamine (8.5 mg, 0.12 mmol, 2 eq.), and then stirred at 25 °C for 2 hour. The reaction mixture was purified by prep- HPLC (C18 column, 0-35 % MeCN in water with 0.05 % TFA) to give (S)-2-amino-N- ((S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3,14-dioxo-3,4,12,14- tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)propenamide (20 mg, yield 61.1 %) as yellow solid. ESI m / z: 565.3 (M+H)+. ’H NMR (500 MHz, DMSO-d6) 59.55 (d, J = 8.7 Hz, 1H), 8.04 (d, J = 12.1 Hz, 1H), 7.30 (s, 1H), 6.52 (s, 1H), 5.72 - 5.17 (m, 6H), 3.64 (q, J = 6.9 Hz, 1H), 3.36 (s, 4H), 2.69 (s, 6H), 1.86 (ddd, J = 21.4, 14.2, 7.0 Hz, 2H), 1.33 (d, J = 7.0 Hz, 3H), 0.87 (t, J = 7.3 Hz, 3H).19F NMR (376 MHz, DMSO-d6) 5 -124.79.

[0358] (S)-2-amino-N-((S)-4-ethyl-8-fluoro-4-hydroxy-ll-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3- oxo-14-thioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)propenamide was prepared in a similar manner. ESI m / z: 565.3 (M+H)+. 'H NMR (400 MHz, DMSO-d6) 5 10.84 (s, 1H), 9.50 (d, J = 8.6 Hz, 1H), 8.30 (s, 3H), 8.15 (d, J = 12.1 Hz, 1H), 7.80 (s, 1H), 6.71 (s, 1H), 5.93 (d, J = 16.7 Hz, 1H), 5.66 (s, 2H), 5.54 (d, J = 16.6 Hz, 1H), 4.34 (d, J = 6.8 Hz, 1H), 3.38 - 3.35 (m, 4H), 2.73 TSRI 2255.1PC / CIB0907P 18350.026WO1

[0359] (s, 6H), 1.98 - 1.81 (m, 2H), 1.53 (d, J = 7.0 Hz, 3H), 0.86 (t, J = 7.3 Hz, 3H).19F NMR (376 MHz, DMSO-d6) 5 -73.47, -120.81.

[0360] 4.6.27. (S)-4-ethyl-8-fluoro-4-hydroxy-9-((2-hydroxyethyl)amino)-ll-(3- methoxybicyclo[l.l.l]pentan-l-yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2- b] quinolin e-3,14(4H)-dione

[0361] To a solution of (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l- yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione (40 mg, 84 pmol, 1 eq.) in THF (0.5 mL) was added ethylene oxide (3.0 mol / L in THF, 0.5 mL, 1.5 mmol, 17.8 eq.) and acetic acid (0.5 mL), and then stirred at 60 °C for 16 hours. The reaction mixture was concentrated under reduced pressure. The residue was purified by prep-HPLC (C18 column, 0-70 % MeCN in water with 0.05 % TFA) to give (S)-4-ethyl-8-fluoro-4-hydroxy-9-((2-hydroxyethyl)amino)-l l-(3- methoxybicyclo[l.l.l]pentan-l-yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline- 3,14(4H)-dione (22 mg, yield 50 %) as yellow solid. ESI m / z: 522.2 (M+H)+. ’H NMR (400 MHz, DMSO-d6) 57.76 (d, J = 12.7 Hz, 1H), 7.24 (d, J = 9.4 Hz, 1H), 7.19 (s, 1H), 6.45 (s, 2H), 5.40 (s, 2H), 5.33 (s, 2H), 3.70 (t, 2H), 3.35 (s, 6H), 2.64 (s, 6H), 1.94 - 1.76 (m, 2H), 0.87 (t, J = 7.3 Hz, 3H).19F NMR (376 MHz, DMSO-d6) 5 -126.06.

[0362] 4.6.28. (S)-4-ethyl-8-fluoro-4-hydroxy-9-(((R)-2-hydroxypropyl)amino)-ll-(3- methoxybicyclo[l.l.l]pentan-l-yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2- b] quinolin e-3,14(4H)-dione

[0363] To a solution of (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l- yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione (40 mg, 84 pmol,l eq.) in THF (1 mL) was added (R)-2 -methyloxirane (116 mg, 2 mmol, 23.8 Eq.) and acetic acid (0.5 mL), and then stirred at 60 °C for 16 hours. The reaction mixture was purified by prep-HPLC (C18 column, 0-70 % MeCN in water with 0.05 % TFA) to give the desired product (15.3 mg) as orange solid, which was purified further by prep-HPLC (C18 column, 0 - 65 % MeCN in water with 0.1 % FA) to give (S)-4- ethyl-8-fluoro-4-hydroxy-9-(((R)-2-hydroxypropyl)amino)- 11 -(3 -methoxybicyclo [ 1.1.1 ]pentan- 1 -yl)- TSRI 2255.1PC / CIB0907P 18350.026WO1 l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione (4.2 mg, yield 9.3 %) as yellow solid. ESI m / z: 536.2 (M+H)+. ’H NMR (400 MHz, DMSO-d6) 57.77 (d, J = 12.8 Hz, 1H), 7.27 (d, J = 9.5 Hz, 1H), 7.19 (s, 1H), 6.47 (d, J = 6.0 Hz, 2H), 5.41 (s, 2H), 5.36 (s, 2H), 4.99 (d, J = 4.6 Hz, 1H), 3.97 (dt, J = 8.3, 6.0 Hz, 1H), 3.35 (s, 3H), 3.27 - 3.18 (m, 2H), 2.68 - 2.62 (m, 6H), 2.01 (d, J = 8.9 Hz, 1H), 1.90 - 1.79 (m, 2H), 1.19 (d, J = 6.2 Hz, 3H), 0.86 (t, J = 7.3 Hz, 3H).19F NMR (376 MHz, DMSO-d6) 5 -126.03.

[0364] 4.6.29. (S)-4-ethyl-8-fluoro-4-hydroxy-9-(((S)-2-hydroxypropyl)amino)-ll-(3- methoxybicyclo[l.l.l]pentan-l-yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2- b] quinolin e-3,14(4H)-dione

[0365] To a solution of To a solution of (S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-l l-(3- methoxybicyclo[l.l.l]pentan-l-yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline- 3,14(4H)-dione (40 mg, 84 pmol,l eq.) in THF (1 mL) was added (S)-2 -methyloxirane (116 mg, 2 mmol, 23.8 Eq.) and acetic acid (0.5 mL), and then stirred at 60 °C for 16 hours. The reaction mixture was purified by prep-HPLC (Cl 8 column, 0-70 % MeCN in water with 0.05 % TFA) to give (S)-4-ethyl-8- fhroro-4-hydroxy-9-(((S)-2-hydroxypropyl)amino)-l 1 -(3 -methoxybicyclo [1.1. l]pentan-l-yl)-l, 12- dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione (14.6 mg) as orange solid, which was purified further by prep-HPLC (Cl 8 column, 0 -65 % MeCN in water with 0.1 % FA) to give the desired compound (3.7 mg, yield 8.2 %) as yellow solid. ESI m / z: 536.1 (M+H)+. *HNMR (400 MHz, DMSO-d6) 57.78 (d, J = 12.8 Hz, 1H), 7.26 (d, J = 9.4 Hz, 1H), 7.19 (s, 1H), 6.48 (s, 1H), 6.11 (d, J = 5.7 Hz, 1H), 5.41 (s, 2H), 5.36 (s, 2H), 4.94 (t, J = 5.5 Hz, 1H), 3.74 - 3.65 (m, 1H), 3.60 (dt, J = 10.7, 5.2 Hz, 1H), 3.50 (dt, J = 11.0, 5.7 Hz, 1H), 3.35 (s, 3H), 2.69 - 2.62 (m, 6H), 1.91 - 1.79 (m, 2H), 1.26 (d, J = 6.4 Hz, 3H), 0.86 (t, J = 7.3 Hz, 3H).19F NMR (376 MHz, DMSO-d6) 5 -125.35.

[0366] TSRI 2255.1PC / CIB0907P 18350.026WO1

[0367] 4.6.30. Representative Compounds

[0368] Particular compounds of the invention include those shown below:

[0369] Table 2 TSRI 2255.1PC / CIB0907P 18350.026WO1 TSRI 2255.1PC / CIB0907P 18350.026WO1 TSRI 2255.1PC / CIB0907P 18350.026WO1 TSRI 2255.1PC / CIB0907P 18350.026WO1

[0370] Deruxtecan (compound 31; Glycinamide, N-[6-(2,5-dihydro-2,5-dioxo-lH-pyrrol-l-yl)-l- oxohexyl]glycylglycyl-L-phenylalanyl-N-[[2-[[(lS,9S)-9-ethyl-5-fluoro-2,3,9,10,13,15-hexahydro-9- hydroxy-4-methyl-10,13-dioxo-lH,12H-benzo[de]pyrano[3',4':6,7]indolizino[l,2-b]quinolin-l-yl]amino]- 2-oxoethoxy]methyl]- (A CI)) was used as a reference compound in assays. 4.6.31. Cytotoxicity Measurements

[0371] The cytotoxicity of compounds of the invention as tested using a CellTiter-Glo® assay (Promega) with multiple cell lines:

[0372] Table 3 The assay was run using the steps described below:

[0373] Cell Seeding: (a) Prepared complete medium: Added FBS and appropriate additives and mixed gently, (b) Checked the cell name and completed medium and passage number marked on the flask. For adherent cell lines, refer to c to k. (c) Removed and discarded culture medium using a vacuum pump, (d) Briefly rinsed the cell layer with 0.25% (w / v) Trypsin-0.038% (w / v) EDTA solution to remove all traces of serum that contained trypsin inhibitor, (e) Added 3.0 ml of Trypsin-EDTA solution to flask and observed cells under an inverted microscope until cell layer was dispersed, (f) Added 9.0 ml of complete TSRI 2255.1PC / CIB0907P 18350.026WO1 growth medium and aspirate cells by gently pipetting, (g) Transferred the cell suspension to a centrifuge tube and centrifuged at 1000 rpm for 4 minutes, (h) Discarded the supernatant using a vacuum pump, (i) Added appropriate volume of complete medium. Suspended the cell pellet by gently pipetting, (j) Counted the cell numbers with Vi-cell XR and adjust cells to appropriate density, (k) Added 36 pL of cell suspension to 384-well opaque-walled clear bottom plates according to the planned plate layout and placed the plates in the CO2 incubator overnight.

[0374] Compound Stock Preparation: (a) The test compounds were dissolved in DMSO of 10 mM stock solution, (b) 0.4 mM Staurosporine was prepared in DMSO at working concentration, (c) Added the compounds to the wells containing 36 pL of the culture medium with HPD300 according to the plate map below and centrifuge at 1000 rpm for 1 minutes. The total dilution was 200 fold.

[0375] Reagent Preparation: (a) Thawed the CellTiter-Glo® buffer and equilibrated to room temperature prior to use. (b) Equilibrated the lyophilized CellTiter-Glo® substrate to room temperature prior to use. (c) Transferred the appropriate volume of CellTiter-Glo® buffer into the amber bottle containing CellTiter-Glo® substrate to reconstitute the lyophilized enzyme / substrate mixture. This formed the CellTiter-Glo reagent, (d) Mixed by gently vortexing, swirling or by inverting the contents to obtain a homogeneous solution.

[0376] Assay Measurement: (a) Observed the cell morphology under an inverted microscope after corresponding treatment, (b) Equilibrated the plate and its contents to room temperature for approximately 30 minutes, (c) Added 25 pL of CellTiter-Glo® reagent to the assay plate by Multidrop Combi instrument, (d) Mixed contents for 10 minutes on an orbital shaker to induce cell lysis, (e) Allowed the plate to incubate at room temperature for 10 minutes to stabilize luminescent signal, (f) Pasted the clear bottom with white back seal and record luminescence with an EnVision™ reader. The settings were: luminescence, measurement time 0.1s.

[0377] Data Analysis: Percent inhibition and IC50 of each compound were calculated with XLFit curve fitting software. Inhibition was calculated by the formula described below:

[0378] Inhibition % = (l-(Tsampie-Tbiank) / (TDMSO-Tbiank))x100%. where Tsampie is the signal from compound-treated wells; Tbiank is the signal from blank wells; and TDMSO is the signal from DMSO-treated wells. Relative IC50 (also referred to as EC50) is half of the maximum inhibitory rate corresponding to the drug concentration. Absolute IC50 is the concentration corresponding to 50% inhibition rate. TSRI 2255.1PC / CIB0907P 18350.026WO1

[0379] Test results for compounds identified in Table 2, above, are provided below. These results show that compounds of the invention are remarkably cytotoxic and may be of particular use in the treatment of cancer.

[0380] Table 4 All publications (e.g. , patents and patent applications) cited above are incorporated herein by reference in their entireties.

Claims

1. TSRI 2255.1PC / CIB0907P 18350.026WO1CLAIMSWhat is claimed is:

1. A compound of formula I:I or a pharmaceutically acceptable salt thereof, wherein:X is O or S;R1is H, halo, R1A, -OR1A, -SR1A, or -S(O)2R1A;R1Ais optionally substituted (Ci-Ce) alkyl, (Ci-Ce) heteroalkyl, (C3-C10) cycloalkyl, (C2-C10) heterocycloalkyl, (C6-Cio) aryl, (C5-C10) heteroaryl, -C(O)(Ci-C6) alkyl, -(Ci-C6) alkyl-NHC(O)-(Ci-C6) alkyl, -(Ci-Ce) alkyl-NHC(O)O-(Ci-C6) alkyl, -(Ci-C6) alkyl-O(Ci-C6) alkyl-NH-C(O)-(Ci-C6) alkyl, or -(Ci-Ce) alkyl-O(Ci-Ce) alkyl-NH-C(O)O-(Ci-Ce) alkyl, which optional substitution is with one or more R1B; each R1Bis independently halo, hydroxy, NO2, R1C, -OR1C, -SR1C, -C(O)Rlc, or -NRBRC; each R1Cis independently H or optionally substituted (Ci-Ce) alkyl, (Ci-Ce) heteroalkyl, (Cs-Cs) cycloalkyl, (C2-Cs) heterocycloalkyl, (Ce-Cio) aryl, or (C5-C10) heteroaryl, which optional substitution is with one or more of halo, hydroxy, NO2, -NHC(O)RA, or -NRBRC;R2is H, amino, halo, RA, or -ORA;R3is H, halo, RA, -ORA, -NRBRC, or -NRBC(O)RA;R4is H, halo, RA, -ORA, or -NRBRC;R5is H, halo, RA, -ORA, or -NRBRC; each RAis independently H or optionally substituted (Ci-Ce) alkyl or (Cs-Cs) cycloalkyl, which optional substitution is with one or more of halo, hydroxy, or -NRBRC; and each of RBand Rcis independently H or optionally substituted -(Ci-Ce) alkyl, -C(O)-(Ci-Ce) alkyl, or -C(O)O-(Ci-Ce) alkyl, which optional substitution is with one or more of amino, halo, or hydroxy; or R2and R3together form a ring, which ring is (C3-C7) cycloalkyl, (C2-Ce) heterocycloalkyl, (Ce- C10) aryl, or (C5-C10) heteroaryl; or R3and R4together form a ring, which ring is (C3-C7) cycloalkyl, (C2-Ce) heterocycloalkyl, (Ce- C10) aryl, or (C5-C10) heteroaryl;TSRI 2255.1PC / CIB0907P 18350.026WO1 or R4and R5together form a ring, which ring is (C3-C7) cycloalkyl, (C2-Ce) heterocycloalkyl, (Ce- C10) aryl, or (C5-C10) heteroaryl.

2. A compound of formula I:I or a pharmaceutically acceptable salt thereof, wherein:X is O or S;R1is H, halo, R1A, -OR1A, -SR1A, or -S(O)2R1A;R1Ais optionally substituted -(Ci-Ce) alkyl, -(Ci-Ce) heteroalkyl, (C3-C10) cycloalkyl, (C2-C10) heterocycloalkyl, (C6-Cio) aryl, (C5-C10) heteroaryl, -C(O)(Ci-C6) alkyl, -(Ci-C6) alkyl-NHC(O)-(Ci-C6) alkyl, -(Ci-Ce) alkyl-NHC(O)O-(Ci-C6) alkyl, -(Ci-C6) alkyl-O(Ci-C6) alkyl-NH-C(O)-(Ci-C6) alkyl, or -(Ci-Ce) alkyl-O(Ci-Ce) alkyl-NH-C(O)O-(Ci-Ce) alkyl, which optional substitution is with one or more R1B; each R1Bis independently halo, hydroxy, NO2, R1C, -OR1C, -SR1C, -C(O)Rlc, or -NRBRC; each R1Cis independently H or optionally substituted -(Ci-Ce) alkyl, -(Ci-Ce) heteroalkyl, (Cs-Cs) cycloalkyl, (C2-Cs) heterocycloalkyl, (Ce-Cio) aryl, or (C5-C10) heteroaryl, which optional substitution is with one or more of halo, hydroxy, NO2, -NHC(O)RA, or -NRBRC;R2is H, amino, halo, RA, or -ORA;R3is H, halo, RA, -ORA, -NRBRC, or -NRBC(O)RA;R4is H, halo, RA, -ORA, or -NRBRC;R5is H, halo, RA, -ORA, or -NRBRC; each RAis independently H or optionally substituted -(Ci-Ce) alkyl or -(Cs-Cs) cycloalkyl, which optional substitution is with one or more of halo, hydroxy, or -NRBRC; and each of RBand Rcis independently H or optionally substituted -(Ci-Ce) alkyl, -C(O)-(Ci-Ce) alkyl, or -C(O)O-(Ci-Ce) alkyl, which optional substitution is with one or more of amino, halo, or hydroxy.

3. The compound of claim 1 or 2, wherein X is O.

4. The compound of claim 1 or 2, wherein R1is H or halo.

5. The compound of claim 1 or 2, wherein R1is R1A.TSRI 2255.1PC / CIB0907P 18350.026WO16. The compound of claim 1 or 2, wherein R1is -OR1A.

7. The compound of claim 1 or 2, wherein R1is -SR1Aor -S(O)2R1A.

8. The compound of any of claims 5-7, wherein R1Ais (Ci-Ce) alkyl.

9. The compound of any of claims 5-7, wherein R1Ais optionally substituted -(Ci-Ce) alkyl- NHC(O)-(CI-C6) alkyl, -(Ci-C6) alkyl-NHC(O)O-(Ci-C6) alkyl, -(Ci-C6) alkyl-O(Ci-C6) alkyl-NH-C(O)- (Ci-Ce) alkyl, or -(Ci-Ce) alkyl-O(Ci-Ce) alkyl-NH-C(O)O-(Ci-Ce) alkyl, which optional substitution is with one or more R1B.

10. The compound of claim 9, wherein R1Bis -NRBRC.

11. The compound of any of the previous claims, wherein if R1is -CH2OH and R3is methyl or methoxy, R4is not fluoro.

12. The compound of any of the previous claims, wherein R2is H.

13. The compound of any of the previous claims, wherein R3is RA.

14. The compound of any of claims 1-12, wherein R3is -ORA.

15. The compound of any of the previous claims, wherein if R3is methyl or methoxy, R4is not fluoro.

16. The compound of any of claims 1-12, wherein R3is -NRBC(O)RA.

17. The compound of any of claims 13, 14 or 16, wherein RAis H or -(Ci-Ce) alkyl.

18. The compound of any of claims 13, 14 or 16, wherein RAis -(Ci-Ce) alkyl optionally substituted with -NRBRC.

19. The compound of any of claims 1-12, wherein R3is -NRBRC.

20. The compound of claim 10, 16, or 19, wherein RBis H.

21. The compound of claim 10, 16, or 19, wherein RBis -(Ci-Ce) alkyl.

22. The compound of claim 10, 18, or 19, wherein Rcis H.

23. The compound of claim 10, 18, or 19, wherein Rcis -(Ci-Ce) alkyl.

24. The compound of claim 10, 18, or 19, wherein each of RBand Rcis H.

25. The compound of any of the previous claims, wherein R4is halo.

26. The compound of any of the previous claims, wherein R5is H.

27. The compound of claim 1, wherein R2and R3together form a ring.

28. The compound of claim 1, wherein R3and R4together form a ring.

29. The compound of claim 1, wherein R4and R5together form a ring.TSRI 2255.1PC / CIB0907P 18350.026WO130. The compound of any of claims 27, 28, or 29, wherein the ring is (C2-Ce) heterocycloalkyl.

31. The compound of claim 30, wherein the ring is 1,3 -dioxolane.

32. The compound of claim 28, wherein the ring is not 1,3 -dioxolane.

33. The compound of claim 28, provided that if the ring is 1,3 -dioxolane, R1is not R1Aor -OR1A.

34. The compound of claim 1 or 2, wherein X is O, R1is -OR1A, and R1Ais optionally substituted -(Ci-Ce) alkyl.

35. The compound of claim 34, wherein R2is H and R5is H.

36. The compound of claim 34 or 35, wherein R3is RAand RAis -NRBRC.

37. The compound of claim 36, wherein RBis H.

38. The compound of claim 36 or 37, wherein Rcis H.

39. The compound of any of claims 34-38, wherein R4is halo.

40. The compound of any of claims 34-39, wherein R5is H.

41. A compound, which is :(S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3-(hydroxymethyl)bicyclo[l.l.l]pentan-l-yl)-9-methyl-l,12- dihydro- 14H-pyrano [3', 4' : 6,7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H) -dione ;(S)-4-ethyl-8,9-difluoro-4-hydroxy- 11 -(3 -(hydroxymethyl)bicyclo [1.1.1 ]pentan- 1 -yl)- 1,12- dihydro- 14H-pyrano [3', 4' : 6,7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H) -dione ;(S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3-(hydroxymethyl)bicyclo[l.l.l]pentan-l-yl)-9-methoxy- 1 , 12-dihydro- 14H-pyrano [3 ',4' : 6, 7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H)-dione;(S)-7-ethyl-7-hydroxy-14-(3-(hydroxymethyl)bicyclo[l.l.l]pentan-l-yl)-10,13-dihydro-l 1H-[1.3]dioxolo[4,5-g]pyrano[3',4':6,7]indolizino[l,2-b]quinoline-8,l l(7H)-dione;(S)-8-ethyl-8-hydroxy-15-(3-(hydroxymethyl)bicyclo[l.l.l]pentan-l-yl)-ll,14-dihydro-12H-[1.3]dioxolo[4,5-f]pyrano[3',4':6,7]indolizino[l,2-b]quinoline-9,12(8H)-dione;(S)-9-amino-4-ethyl-8-fluoro-4-hydroxy- 11 -(3 -methylbicyclo [1.1.1 ]pentan- 1 -yl)- 1 , 12-dihydro- 14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione;(S)-9-amino-l 1 -(bicyclo [1.

1. l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-l, 12-dihydro-14H- pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione;(S)-9-amino-4-ethyl-8-fluoro-4-hydroxy- 11 -(3 -methoxybicyclo [1.1.1 ]pentan- 1 -yl)- 1 , 12-dihydro- 14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione;(S)-9-amino-4-ethyl-8-fluoro-l 1 -(3 -fluorobicyclo [1.

1. l]pentan-l-yl)-4-hydroxy-l, 12-dihydro- 14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline-3,14(4H)-dione;TSRI 2255.1PC / CIB0907P 18350.026WO1(S)-9-amino-4-ethyl-8-fluoro-4-hydroxy-l 1 -(3 -methoxybicyclo [1.

1. l]pentan-l-yl)-14-thioxo-12.14-dihydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-3(4H)-one;(R)-14-(bicyclo[l.l.l]pentan-l-yl)-7-ethyl-7-hydroxy-10,13-dihydro-l lH-[l,3]dioxolo[4,5- g]pyrano[3',4':6,7]indolizino[l,2-b]quinoline-8,l l(7H)-dione;(S)-2-amino-N-(((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH- pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l-yl)methoxy)methyl)acetamide;(S)-2-amino-N-(2-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH- pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l-yl)oxy)ethyl)acetamide;(S)-l 1 -(3-(2 -aminoethoxy )bicy clo[ 1.

1. l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-l, 12- dihydro- 14H-pyrano [3', 4' : 6,7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H) -dione ;2-hydroxyethyl (S)-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3, 14-dioxo-3,4, 12, 14-tetrahydro- IH-pyrano [3 ',4' : 6,7]indolizino [ 1 ,2-b] quinolin- 11 -yl)bicyclo [1.1.1 ]pentan- 1 -yl)methyl)carbamate;(S)-N-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH- pyrano[3',4':6,7]indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l-yl)methyl)-3- hydroxypropanamide ;(S)-N-((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3,14-dioxo-3,4,12,14-tetrahydro-lH- pyrano[3', 4':6, 7] indolizino[l,2-b]quinolin-ll-yl)bicyclo[l.l.l]pentan-l-yl)methyl)-2 -hydroxyacetamide;(S)-l l-(3-(aminomethyl)bicyclo[l.l.l]pentan-l-yl)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-l,12- dihydro- 14H-pyrano [3', 4' : 6,7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H) -dione ;(S)-2-amino-N-((2-(((3-(4-ethyl-8-fluoro-4-hydroxy-9-methyl-3, 14-dioxo-3,4, 12, 14-tetrahydro- IH-pyrano [3 ',4' : 6,7]indolizino [ 1 ,2-b] quinolin- 11 -yl)bicyclo [1.1.1 ]pentan- 1 -yl)methyl)amino)-2- oxoethoxy)methyl)acetamide ;(S)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-l l-(3-(methylthio)bicyclo[l .

1. l]pentan-l-yl)-l, 12- dihydro- 14H-pyrano [3', 4' : 6,7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H) -dione ;(S)-4-ethyl-8-fluoro-4-hydroxy-9-methoxy-l l-(3-(methylsulfonyl)bicyclo[l .

1. l]pentan-l-yl)- 1 , 12-dihydro- 14H-pyrano [3 ',4' : 6, 7] indolizino [ 1 ,2-b] quinoline-3 , 14(4H)-dione;(S)-N-(4-ethyl-8-fluoro-4-hydroxy- 11 -(3 -methoxybicyclo [ 1.

1. l]pentan-l-yl)-3, 14-dioxo-3.4.12.14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)-3-hydroxypropanamide;(S)-4-ethyl-8-fluoro-4-hydroxy-9-((2-hydroxyethyl)amino)- 11 -(3 -methoxybicyclo [ 1.

1. l]pentan- 1 -yl)- 1 , 12-dihydro- 14H-pyrano [3 ',4' : 6,7]indolizino [ 1 ,2-b] quinoline-3 , 14(4H)-dione ;(R)-N-((S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3,14-dioxo-3.4.12.14-tetrahydro-lH-pyrano[3', 4':6, 7] indolizino[l,2-b]quinolin-9-yl)-2 -hydroxypropanamide;(S)-N-((S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3,14-dioxo-3, 4, 12, 14-tetrahydro-lH-pyrano[3', 4':6, 7] indolizino[l,2-b]quinolin-9-yl)-2 -hydroxypropanamide;(S)-2-amino-N-((S)-4-ethyl-8-fluoro-4-hydroxy-l l-(3-methoxybicyclo[l.l.l]pentan-l-yl)-3,14- dioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)propenamide;TSRI 2255.1PC / CIB0907P 18350.026WO1(S)-2-amino-N-((S)-4-ethyl-8-fluoro-4-hydroxy-l 1 -(3 -methoxybicyclo [1.

1. l]pentan-l-yl)-3-oxo- 14-thioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)propenamide;(R)-N-((S)-4-ethyl-8-fluoro-4-hydroxy-l 1 -(3 -methoxybicyclo [1.

1. l]pentan-l-yl)-3-oxo-14- thioxo-3,4,12,14-tetrahydro-lH-pyrano[3',4':6,7]indolizino[l,2-b]quinolin-9-yl)-2-hydroxypropanamide;(S)-4-ethyl-8-fluoro-4-hydroxy-9-(((R)-2-hydroxypropyl)amino)-l l-(3- methoxybicyclo[l. l.l]pentan-l-yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline- 3,14(4H)-dione;(S)-4-ethyl-8-fluoro-4-hydroxy-9-(((S)-2-hydroxypropyl)amino)-l l-(3- methoxybicyclo[l. l.l]pentan-l-yl)-l,12-dihydro-14H-pyrano[3',4':6,7]indolizino[l,2-b]quinoline- 3,14(4H)-dione; or a pharmaceutically acceptable salt thereof.

42. An antibody-drug conjugate (ADC) of the formula:Ab-(L-X)„ wherein Ab is a monoclonal antibody, L is a cleavable linker, X is a compound of any of claims 1-41, and n is 1-10.

43. The ADC of claim 42, wherein the Ab binds to Alkaline Phosphatase Placental -like 2 (ALPPL2); B7 homolog 3 (B7-H3); B7 homolog 4 (B7-H4); Cadherin 6 (CDH6); Claudin 6 (CLDN6); Claudin 18 isoform 2 (CLDN18.2); Cluster of Differentiation 30 (CD30); CUB Domain Containing Protein 1 (CDCP1); Delta-like protein 3 (DLL3); Epidermal Growth Factor Receptor (EGFR); Folate Receptor Alpha (FRa); Glypican 3 (GPC3); Human Epidermal Growth Factor Receptor 2 (HER2); Human Epidermal Growth Factor Receptor 3 (HER3); Interleukin-3 receptor alpha chain (CD 123); Mesenchymal-Epithelial Transition factor (cMet); Mesothelin (MSLN); Nectin-4; Prostate-Specific Membrane Antigen (PSMA); Programmed Death-Ligand 1 (PD-L1); Tissue Factor (TF); Six- Transmembrane Epithelial Antigen of the Prostate 1 (STEAP1); Trophoblast cell surface antigen 2 (TROP2); or Tumor-Associated Calcium Signal Transducer 2 (TROP2).

44. A composition comprising the compound or ADC of any of the previous claims and a pharmaceutically acceptable carrier, diluent, or excipient.

45. A method of treating cancer, which comprises administering to a patient in need thereof a therapeutically effective amount of a compound of any of claims 1-41, an ADC of claims 42 or 43, or a composition of claim 44.

46. The method of claim 45, wherein the cancer is bladder cancer, brain cancer, breast cancer, colorectal cancer, kidney cancer, lung cancer, ovarian cancer, pancreatic cancer, or prostate cancer.

Images