Process for preparing functionalized cyclooctene

Abstract

To provide a process for preparing functionalized cyclooctene.SOLUTION: The present disclosure relates to a process for preparing functionalized cyclooctene, and a synthetic intermediate prepared by the process. The present disclosure relates to a method for preparing a functionalized payload composition for delivering a therapeutic drug to a subject, which has improved water solubility, and is to be used by such reaction. The functionalized payload has improved water solubility compared to a payload connected to unsubstituted cyclooctene, and therefore is compounded and administered more easily.SELECTED DRAWING: None

Description

Technical Field

[0001] Cross - reference to related applications This application claims the benefit of U.S. Provisional Patent Application No. 62 / 744,041, filed Oct. 10, 2018, under 35 U.S.C. § 119(e), the entire disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to a process for preparing a functionalized cyclooctene and to synthetic intermediates prepared thereby.

Background Art

[0003] Bioorthogonal conjugation or click reactions are selective orthogonal (non - interacting) functions found in biological systems and are used in various applications in the fields of chemistry, chemical biology, molecular diagnostics, and medicine. They can be used to facilitate the selective manipulation of molecules, cells, particles, and surfaces, as well as the tagging and tracking of biomolecules in vitro and in vivo. These reactions include the Staudinger ligation, azide - cyclooctene cycloaddition, and inverse electron demand Diels - Alder reactions. This disclosure provides a method for preparing a functionalized payload composition for use in such reactions, having improved water solubility for delivering therapeutic agents to a subject.

Summary of the Invention

Means for Solving the Problems

[0004] The functionalized payload according to the present disclosure has improved water solubility compared to a payload linked to an unsubstituted cyclooctene and is thus more easily formulated and administered.

[0005] Provided herein is a compound of Formula I

Chemical Formula

Chemical formula

Chemical formula

[0006] Also, a compound of formula X

Chemical formula

Chemical formula

Chemical formula

[0007] Also, a process for preparing a compound of formula I (wherein R is -OR, an optionally substituted heterocyclyl, and an amino acid moiety selected from the group consisting of, n is 0, 1, 2, 3 or 4, each R is independently C alkyl, C haloalkyl, and C alkoxy, D is a payload moiety, and R is hydrogen or C alkyl) or a salt thereof, comprising contacting a compound of formula X or a salt thereof with a payload moiety or a salt thereof in the presence of a base in an organic solvent is also provided.

Chemical formula

Chemical formula

[0008] Also, a compound of formula IV

Chemical formula

Chemical formula

[0009] (wherein,

Chemical formula

[0010] In certain embodiments, the process includes repeating steps (b) and (c) before step (d).

[0011] Also, a process for preparing an enantiomerically enriched composition comprising a compound of formula VII

Chem.

Chem.

[0012] Also, a process for resolving a composition comprising one or more stereoisomers of a compound of formula VIIA

Chem.

[0013] Also, a compound of formula VB

Chemical formula

Chemical formula

[0014] Also provided is an enantiomerically enriched composition comprising a compound selected from Table 1 or a salt thereof.

Mode for Carrying Out the Invention

[0015] 1. Definitions Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present specification including the definitions will control. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.

[0016] The terms "comprise", "include", "having", "has", "can", "contain", and variations thereof, as used herein, are intended to be open transitional phrases, terms, or words that do not preclude the possibility of additional acts or structures. The singular forms "a", "and", and "the" include plural referents unless the context clearly dictates otherwise. The present disclosure also contemplates other embodiments that "comprise", "consist of", and "consist essentially of" the embodiments or elements presented herein, whether or not explicitly recited.

[0017] The modifier "about", when used in relation to a quantity, includes the recited value and has the meaning as defined by the context (e.g., including the degree of error associated with the measurement of at least a particular quantity). The modifier "about" should also be considered to disclose a range defined by the absolute values of two endpoints. For example, the expression "about 2 to about 4" also discloses the range of "2 to 4". The term "about" can refer to plus or minus 10% of the number shown. For example, "about 10%" may indicate the range of 9% to 11%, and "about 1" may mean the range of 0.9 to 1.1. Other meanings of "about" may become apparent from the context such as rounding, etc., so for example, "about 1" may in some cases mean 0.5 to 1.4.

[0018] The conjunction "or" includes any and all combinations of one or more of the recited elements associated by this conjunction. For example, the phrase "an apparatus including A or B" can refer to an apparatus including A without B, an apparatus including B without A, or an apparatus including both A and B. The expressions "at least one of A, B, … and N" or "at least one of A, B, … N, or combinations thereof" are defined most broadly to mean one or more elements selected from the group consisting of A, B, … and N, in other words, defined most broadly to mean one or more combinations of one or more of the elements A, B, … or N, including only any one element alone or in combination with one or more of the other elements that may include additional elements not recited.

[0019] Definitions of specific functional groups and chemical terms are described in more detail below. For the purposes of this disclosure, chemical elements are identified according to the inside front cover of the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75th Ed., and specific functional groups are generally defined as described therein. Further, general principles of organic chemistry, as well as specific functional moieties and reactivities, are described in Organic Chemistry, Thomas Sorrell, University Science Books, Sausalito, 1999; Smith and March March’s Advanced Organic Chemistry, 5th Edition, John Wiley & Sons, Inc., New York, 2001; Larock, Comprehensive Organic Transformations, VCH Publishers, Inc., New York, 1989; Carruthers, Some Modern Methods of Organic Synthesis, 3rd Edition, Cambridge University Press, Cambridge, 1987, the entire contents of each of which are hereby incorporated by reference into this specification.

[0020] As used herein, the term "enantiomerically enriched" refers to a composition of a chiral substance having an enantiomeric ratio greater than 50:50 but less than 100:0. In certain embodiments, an enantiomerically enriched composition has greater than about 25%, or greater than about 30%, or greater than about 35%, or greater than about 40%, or greater than about 45%, or greater than about 50%, or greater than about 55%, or greater than about 60%, or greater than about 65%, or greater than about 70%, or greater than about 75%, or greater than about 80%, or greater than about 85%, or greater than about 90%, or greater than about 95%, or greater than about 97%, or greater than about 99%, or about 25%, or about 30%, or about 35%, or about 40%, or about 45%, or about 50%, or about 55%, or about 60%, or about 65%, or about 70%, or about 75%, or about 80%, or about 85%, or about 90%, or about 95%, or about 97%, or about 99%, or about 100% ee.

[0021] As used herein, the term "alkyl" means a straight or branched saturated hydrocarbon chain containing from 1 to 30 carbon atoms. The term "lower alkyl" or "C1-C6-alkyl" means a straight or branched chain hydrocarbon containing from 1 to 6 carbon atoms. The term "C1-C3-alkyl" means a straight or branched chain hydrocarbon containing from 1 to 3 carbon atoms. Representative examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, iso-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, 3-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, n-heptyl, n-octyl, n-nonyl, and n-decyl.

[0022] As used herein, the term "alkoxy" refers to an alkyl group as defined herein attached to the parent molecular moiety through an oxygen atom. Representative examples of alkoxy include, but are not limited to, methoxy, ethoxy, propoxy, 2-propoxy, butoxy and tert-butoxy.

[0023] As used herein, the term "alkenyl" means a hydrocarbon chain containing 2 to 30 carbon atoms having at least one carbon-carbon double bond. The alkenyl group may be substituted or unsubstituted. For example, the alkenyl group may be substituted with an aryl group such as phenyl.

[0024] As used herein, the term "alkynyl" refers to a straight or branched monovalent hydrocarbyl group having 2 to 30 carbon atoms, such as 2 to 20 or 2 to 10 carbon atoms, and having at least one site of triple bond unsaturation. The term "alkyne" also includes non-aromatic cycloalkyl groups having 5 to 20 carbon atoms, such as 5 to 10 carbon atoms, having a single or multiple rings and having at least one triple bond. Examples of such alkynyl groups include, but are not limited to, ethynyl (-C≡CH) and propargyl (-CH2C≡CH) and cycloalkynyl moieties, such as, but not limited to, substituted or unsubstituted cyclooctyne moieties.

[0025] As used herein, the term "alkoxyalkyl" refers to an alkoxy group as defined herein attached to a parent molecular moiety via an alkyl group as defined herein.

[0026] As used herein, the term "alkylene" refers to a divalent group derived from a straight or branched chain hydrocarbon having 1 to 30 carbon atoms, such as 2 to 10 carbon atoms. Representative examples of alkylene include, but are not limited to, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, and -CH2CH2CH2CH2CH2-.

[0027] As used herein, the term "aryl" refers to a phenyl group, or a fused ring system of a bicyclic aryl or tricyclic aryl. The bicyclic fused ring system is exemplified by a phenyl group added to the parent molecular moiety and fused to a phenyl group. The tricyclic fused ring system is exemplified by a phenyl group added to the parent molecular moiety and fused to two other phenyl groups. Representative examples of bicyclic aryl include, but are not limited to, naphthyl. Representative examples of tricyclic aryl include, but are not limited to, anthracenyl. Monocyclic, bicyclic, and tricyclic aryl are connected to the parent molecular moiety via any carbon atom contained within the ring and may be unsubstituted or substituted.

[0028] As used herein, the term "cycloalkyl" refers to a carbocyclic ring system containing 3 to 10 carbon atoms, zero heteroatoms, and zero double bonds. Representative examples of cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl. "Cycloalkyl" also includes a carbocyclic ring system in which a cycloalkyl group is added to the parent molecular moiety and fused to an aryl group as defined herein, a heteroaryl group as defined herein, or a heterocycle as defined herein.

[0029] As used herein, the term "cycloalkenyl" means a non-aromatic monocyclic or polycyclic system containing at least one carbon-carbon double bond and preferably having 5 to 10 carbon atoms per ring. Exemplary monocyclic cycloalkenyl rings include, but are not limited to, cyclopentenyl, cyclohexenyl, or cycloheptenyl.

[0030] As used herein, the term "cyclooctene" refers to a substituted or unsubstituted non-aromatic cyclic alkyl group of 8 carbon atoms having a single ring with a double bond. Examples of such cyclooctene groups include, but are not limited to, substituted or unsubstituted trans-cyclooctene (TCO).

[0031] As used herein, the term "fluoroalkyl" means an alkyl group as defined herein in which one, two, three, four, five, six, seven, or eight hydrogen atoms are replaced by fluorine. Representative examples of fluoroalkyl include, but are not limited to, 2-fluoroethyl, 2,2,2-trifluoroethyl, trifluoromethyl, difluoromethyl, pentafluoroethyl, and trifluoropropyl such as 3,3,3-trifluoropropyl.

[0032] As used herein, the term "alkoxyfluoroalkyl" refers to an alkoxy group as defined herein that is attached to the parent molecular moiety via a fluoroalkyl group as defined herein.

[0033] As used herein, the term "fluoroalkoxy" means that at least one fluoroalkyl group as defined herein is attached to the parent molecular moiety via an oxygen atom. Representative examples of fluoroalkyloxy include, but are not limited to, difluoromethoxy, trifluoromethoxy, and 2,2,2-trifluoroethoxy.

[0034] As used herein, the term "halogen" or "halo" means Cl, Br, I, or F.

[0035] As used herein, the term "haloalkyl" means an alkyl group as defined herein in which one, two, three, four, five, six, seven, or eight hydrogen atoms are replaced by halogen.

[0036] As used herein, the term "haloalkoxy" means that at least one haloalkyl group as defined herein is attached to the parent molecular moiety via an oxygen atom.

[0037] As used herein, the term "heteroalkyl" means an alkyl group as defined herein in which one or more of the carbon atoms are replaced by heteroatoms selected from S, Si, O, P, and N. The heteroatoms may be oxidized. Representative examples of heteroalkyl include, but are not limited to, alkyl ethers, secondary and tertiary alkyl amines, and alkyl sulfides.

[0038] As used herein, the term "heteroaryl" refers to an aromatic monocyclic, bicyclic, or tricyclic system. The aromatic monocyclic ring is a 5- or 6-membered ring containing at least one heteroatom independently selected from the group consisting of N, O, and S (e.g., 1, 2, 3, or 4 heteroatoms independently selected from O, S, and N). The 5-membered aromatic monocyclic ring has two double bonds, and the 6-membered aromatic monocyclic ring has three double bonds. The bicyclic heteroaryl group is attached to the parent molecular moiety and is exemplified by a monocyclic heteroaryl ring fused to a monocyclic cycloalkyl group as defined herein, a monocyclic aryl group as defined herein, a monocyclic heteroaryl group as defined herein, or a monocyclic heterocycle as defined herein. The tricyclic heteroaryl group is attached to the parent molecular moiety and is exemplified by a monocyclic heteroaryl ring fused to two of a monocyclic cycloalkyl group as defined herein, a monocyclic aryl group as defined herein, a monocyclic heteroaryl group as defined herein, or a monocyclic heterocycle as defined herein. Representative examples of monocyclic heteroaryl include, but are not limited to, pyridinyl (including pyridin-2-yl, pyridin-3-yl, pyridin-4-yl), pyrimidinyl, pyrazinyl, thienyl, furyl, thiazolyl, thiadiazolyl, isoxazolyl, pyrazolyl, and 2-oxo-1,2-dihydropyridinyl. Representative examples of bicyclic heteroaryl include, but are not limited to, chromenyl, benzothienyl, benzodioxolyl, benzotriazolyl, quinolinyl, thienopyrrolyl, thienothienyl, imidazothiazolyl, benzothiazolyl, benzofuranyl, indolyl, quinolinyl, imidazopyridine, benzoxadiazolyl, and benzopyrazolyl. Representative examples of tricyclic heteroaryl include, but are not limited to, dibenzofuranyl and dibenzothienyl. Monocyclic, bicyclic, and tricyclic heteroaryl are attached to the parent molecular moiety through any carbon atom or any nitrogen atom contained within the ring and may be unsubstituted or substituted.

[0039] As used herein, the terms "heterocyclic ring" or "heterocyclic" mean a monocyclic heterocyclic ring, a bicyclic heterocyclic ring, or a tricyclic heterocyclic ring. A monocyclic heterocyclic ring is a 3-, 4-, 5-, 6-, 7-, or 8-membered ring containing at least one heteroatom independently selected from the group consisting of O, N, and S. A 3-membered or 4-membered ring contains 0 or 1 double bond and 1 heteroatom selected from the group consisting of O, N, and S. A 5-membered ring contains 0 or 1 double bond and 1, 2, or 3 heteroatoms selected from the group consisting of O, N, and S. A 6-membered ring contains 0, 1, or 2 double bonds and 1, 2, or 3 heteroatoms selected from the group consisting of O, N, and S. A 7-membered and 8-membered ring contains 0, 1, 2, or 3 double bonds and 1, 2, or 3 heteroatoms selected from the group consisting of O, N, and S. Representative examples of monocyclic heterocyclic rings include, but are not limited to, azetidinyl, azepanyl, aziridinyl, diazepanyl, 1,3-dioxanyl, 1,3-dioxolanyl, 1,3-dithiolanyl, 1,3-dithianyl, 1,3-dimethylpyrimidine-2,4(1H,3H)-dione, imidazolinyl, imidazolidinyl, isothiazolinyl, isothiazolidinyl, isoxazolinyl, isoxazolidinyl, morpholinyl, oxadiazolinyl, oxadiazolidinyl, oxazolinyl, oxazolidinyl, oxetanyl, piperazinyl, piperidinyl, pyranyl, pyrazolinyl, pyrazolidinyl, pyrrolinyl, pyrrolidinyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydropyridinyl, tetrahydrothienyl, thiadiazolinyl, thiadiazolidinyl, 1,2-thiadinanyl, 1,3-thiadinanyl, thiazolinyl, thiazolidinyl, thiomorpholinyl, 1,1-dioxidothiomorpholinyl (thiomorpholine sulfone), thiopyranyl, and trithianyl.The bicyclic heterocyclic ring is a monocyclic heterocyclic ring condensed with a phenyl group, or a monocyclic heterocyclic ring condensed with a monocyclic cycloalkyl, or a monocyclic heterocyclic ring condensed with a monocyclic cycloalkenyl, or a monocyclic heterocyclic ring condensed with a monocyclic heterocyclic ring, or a spiro heterocyclic ring, or a bridged monocyclic heterocyclic ring system in which two non-adjacent atoms of the ring are linked by an alkylene bridge of 1, 2, 3, or 4 carbon atoms, or an alkenylene bridge of 2, 3, or 4 carbon atoms. Representative examples of the bicyclic heterocyclic ring include, but are not limited to, benzopyranyl, benzothiopyranyl, chromanyl, 2,3-dihydrobenzofuranyl, 2,3-dihydrobenzothienyl, 2,3-dihydroisoquinoline, 2-azaspiro[3.3]heptan-2-yl, azabicyclo[2.2.1]heptyl (including 2-azabicyclo[2.2.1]heptan-2-yl), 2,3-dihydro-1H-indolyl, isoindolinyl, octahydrocyclopenta[c]pyrrolyl, octahydropyrrolopyridinyl, and tetrahydroisoquinolinyl. The tricyclic heterocyclic ring is exemplified by a bicyclic heterocyclic ring condensed with a phenyl group, or a bicyclic heterocyclic ring condensed with a monocyclic cycloalkyl, or a bicyclic heterocyclic ring condensed with a monocyclic cycloalkenyl, or a bicyclic heterocyclic ring condensed with a monocyclic heterocyclic ring, or a bicyclic heterocyclic ring in which two non-adjacent atoms of the bicyclic ring are linked by an alkylene bridge of 1, 2, 3, or 4 carbon atoms, or an alkenylene bridge of 2, 3, or 4 carbon atoms. Examples of the tricyclic heterocyclic ring include, but are not limited to, octahydro-2,5-epoxypentalene, hexahydro-2H-2,5-methanocyclopenta[b]furan, hexahydro-1H-1,4-methanocyclopenta[c]furan, aza-adamantane (1-azatricyclo[3.3.1.13,7]decane), and oxa-adamantane (2-oxatricyclo[3.3.1.13,7]decane). The monocyclic, bicyclic, and tricyclic heterocyclic rings are connected to the parent molecular moiety via any carbon atom or any nitrogen atom contained within the ring and may be unsubstituted or substituted.

[0040] As used herein, the term "hydroxyl" means an -OH group.

[0041] As used herein, the term "hydroxyalkyl" means an alkyl group as defined herein, wherein 1, 2, 3, 4, 5, 6, 7 or 8 hydrogen atoms are replaced by hydroxyl groups.

[0042] In some cases, the number of carbon atoms in a hydrocarbyl substituent (e.g., alkyl or cycloalkyl) is indicated by the prefix "C x -C y - " or "C x-y ", where x is the minimum number of carbon atoms in the substituent and y is the maximum number. Thus, for example, "C1-C3-alkyl" and "C1-3 alkyl" refer to alkyl substituents containing 1 to 3 carbon atoms. The two notations "C x -C y -" and "C x-y " are used interchangeably and have the same meaning.

[0043] The term "substituted" refers to a group that can be further substituted with one or more non-hydrogen substituents. Substituents include, but are not limited to, halogen, =O, =S, cyano, nitro, fluoroalkyl, alkoxyfluoroalkyl, fluoroalkoxy, alkyl, alkenyl, alkynyl, haloalkyl, haloalkoxy, heteroalkyl, cycloalkyl, cycloalkenyl, aryl, heteroaryl, heterocycle, cycloalkylalkyl, heteroarylalkyl, arylalkyl, hydroxy, hydroxyalkyl, alkoxy, alkoxyalkyl, alkylene, aryloxy, phenoxy, benzyloxy, amino, alkylamino, acylamino, aminoalkyl, arylamino, sulfonylamino, sulfinylamino, sulfonyl, alkylsulfonyl, arylsulfonyl, aminosulfonyl, sulfinyl, -COOH, ketone, amide, carbamate, and acyl.

[0044] The term "therapeutic agent" refers to an agent that can treat and / or ameliorate a condition or disease of a subject, or one or more symptoms thereof. The therapeutic agents of the present disclosure also include prodrug forms of therapeutic agents.

[0045] The term "diagnostic agent" refers to an agent that aids in the diagnosis of a condition or disease. Representative diagnostic agents include contrast agents such as paramagnetic agents, optical probes, and radionuclides. A paramagnetic agent is a contrast agent that becomes magnetic under an externally applied magnetic field. Examples of paramagnetic agents include, but are not limited to, iron particles including iron nanoparticles and iron microparticles. An optical probe is a fluorescent compound that can be detected by excitation with radiation of one wavelength and detection with radiation of a second, different wavelength. The optical probes of the present disclosure include, but are not limited to, Cy5.5, Alexa 680, Cy5, DiD (1,1'-dioctadecyl-3,3,3',3'-tetramethylindodicarbocyanine perchlorate), and DiR (1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide). Other optical probes include quantum dots. A radionuclide is an element that undergoes detectable radioactive decay. Radionuclides useful in embodiments of the present disclosure include, but are not limited to, 3 H, 11 C, 13 N, 18 F, 19 F, 60 Co, 64 Cu, 67 Cu, 68 Ga, 82 Rb, 90 Sr, 90 Y, 99 Tc, 99m Tc, 111 In, 123 I, 124 I, 125 I, 129 I, 131 I, 137 Cs, 177 Lu, 186 Re, 188 Re, 211 At, Rn, Ra, Th, U, Pu, and 241 Am.

[0046] The terms "contacting" or "contact" refer to a process of bringing at least two different species into contact such that, as a result, they can act on each other through non-covalent or covalent interactions or binding reactions, etc. However, it should be understood that the resulting complex or reaction product can be directly from the interaction or reaction between the added reagents, or can be generated from an intermediate from one or more of the added reagents or moieties, and can be formed in the contact mixture.

[0047] The term "leaving group" refers to an atom (or group of atoms) having an electron-withdrawing ability that can be substituted as a stable species with associated bonding electrons. Examples of suitable leaving groups include halides (e.g., Br, Cl, I), sulfonic acid esters (e.g., triflate, mesylate, tosylate, and brosylate), and nitrophenol.

[0048] The term "physiological conditions" means conditions that are compatible with living cells, including mainly aqueous conditions such as temperature, pH, salinity, etc. that are compatible with living cells.

[0049] The term "chiral base" is meant to encompass chiral compounds having at least one stereocenter and at least one nitrogen atom. Chiral bases can be synthesized using methods known in the art or purchased from commercial sources (e.g., Sigma Aldrich). Exemplary chiral bases include, but are not limited to, L-(-)-α-amino-ε-caprolactam hydrochloride, (R)-(-)-1-amino-2-propanol, (S)-(+)-1-amino-2-propanol, L-aspartic acid, cis-(1S,2R)-(-)-2-(benzylamino)cyclohexanemethanol, (S)-N-benzyl-1-(1-naphthyl)ethylamine hydrochloride, (-)-1,4-bis-O-(4-chlorobenzyl)-L-threitol, (1R,2R)-1,2-bis(2-hydroxyphenyl)ethylenediamine, (1S,2S)-1,2-bis(2-hydroxyphenyl)ethylenediamine, (+)-bis[(R)-1-phenylethyl]amine hydrochloride, N,N-bis[(S)-(-)-1-phenylethyl]phthalic acid, (R)-(+)-1-(4-bromophenyl)ethylamine, (S)-(-)-1-(4-bromophenyl)ethylamine, (R)-4-chloro-α-methylbenzylamine, (S)-4-chloro-α-methylbenzylamine, cinchonidine, (+)-cinchonine, (R)-(+)-N,α-dimethylbenzylamine, (S)-(-)-N,α-dimethylbenzylamine, (R)-(+)-N,N-dimethyl-1-phenylethylamine, (S)-(-)-N,N-dimethyl-1-phenylethylamine, (R)-5,5-dimethyl-6-phenyl-3,4,5,6-tetrahydropyrimidine, (S)-5,5-dimethyl-6-phenyl-3,4,5,6-tetrahydropyrimidine, (R)-(-)-3,5-dinitro-N-(1-phenylethyl)benzamide, (S)-(+)-3,5-dinitro-N-(1-phenylethyl)benzamide, (1R,(2S)-(-)-Ephedrine, D-glutamic acid, L-glutamic acid, (R)-(+)-α-methylbenzylamine, (S)-(-)-α-methylbenzylamine, (R)-α-methyl-4-nitrobenzylamine hydrochloride, (S)-α-methyl-4-nitrobenzylamine hydrochloride, (R)-(+)-α-methyl-4-pyridinemethanol, (S)-(-)-α-methyl-4-pyridinemethanol, (S)-(-)-1-(2-naphthyl)ethylamine, (S)-(-)-N-[1-(1-naphthyl)ethyl]succinic acid, (R)-(+)-N-(1-phenylethyl)phthalic acid, (S)-(-)-N-(1-phenylethyl)phthalic acid, (R)-(+)-N-(1-phenylethyl)succinic acid, (S)-(-)-N-(1-phenylethyl)succinic acid, quinine, D-valine, and L-valine are mentioned.,

[0050] In the case of the compounds described herein, the groups and substituents thereof can be selected according to the acceptable valences of the atoms and substituents, such that the selection and substitution result in a stable compound that does not spontaneously undergo conversions such as rearrangement, cyclization, elimination, etc., for example.,

[0051] When a range of values is provided, each intervening value between the upper and lower limits of that range, as well as any other specified or intervening value within the specified range, is to be understood as being included in the present invention to the tenth of the unit of the lower limit, unless the context clearly indicates otherwise. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and can be included in the present invention subject to any specifically excluded value within the specified range. When the described range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the present invention.,

[0052] Regarding the recitation of numerical ranges in this specification, each numerical value intervening therebetween is explicitly contemplated with the same degree of precision. For example, in the range of 6 to 9, in addition to 6 and 9, the numbers 7 and 8 are contemplated, and in the range of 6.0 to 7.0, the numbers 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are explicitly contemplated.

[0053] It should also be understood that specific features of the invention that are described in the context of separate embodiments for clarity may be provided in combination in a single embodiment. Conversely, various features of the invention that are described in the context of a single embodiment for brevity may be provided separately or in any suitable sub-combination. All combinations of embodiments relevant to this specification are specifically encompassed by the invention and are disclosed herein as if every possible combination was individually and explicitly disclosed, provided that such combinations include, for example, a subject matter that is a compound that is a stable compound (i.e., a compound that can be made, isolated, characterized, and tested for biological activity). Further, all sub-combinations of various embodiments and their elements (e.g., elements of chemical groups recited in embodiments that describe such variables) are also specifically encompassed by the invention and are disclosed herein as if every such sub-combination was individually and explicitly disclosed herein.

[0054] 2. Process The processes described herein provide a functionalized payload having improved water solubility compared to a payload linked to unsubstituted cyclooctene. The functionalized payload can be used as a reagent in bioorthogonal couplings or click reactions and has been used in various applications in the fields of chemistry, chemical biology, molecular diagnostics, and medicine, and can be used to facilitate the selective manipulation of molecules, cells, particles, and surfaces, as well as the tagging and tracking of biomolecules in vitro and in vivo. The processes described herein are carried out under suitable reaction conditions and, optionally, using one or more protecting groups as necessary.

[0055] The term "reaction conditions" is intended to refer to the physical and / or environmental conditions under which a chemical reaction proceeds. Examples of reaction conditions include, but are not limited to, one or more of the following: reaction temperature, solvent, pH, pressure, reaction time, molar ratio of reactants, base or acid, one or more protecting groups, or the presence of a catalyst, radiation, etc. Reaction conditions may be named according to the particular chemical reaction in which they are used, such as coupling conditions, hydrogenation conditions, acylation conditions, reduction conditions, etc. The reaction conditions for most reactions are generally known to those of ordinary skill in the art or can be readily obtained from the literature. Exemplary reaction conditions sufficient to effect the chemical transformations provided herein can be found throughout, and in particular in the following examples. Reaction conditions are also contemplated to include reagents in addition to those listed for a particular reaction.

[0056] The term "protecting group" refers to a group that is intended to protect a given atom or functional group from unwanted reactions during a synthetic procedure, and includes, but is not limited to, silyl ethers such as 2-(trimethylsilyl)ethoxymethyl (SEM) ether, or alkoxymethyl ethers such as methoxymethyl (MOM) ether, tert-butoxymethyl (BUM) ether, benzyloxymethyl (BOM) ether or methoxyethoxymethyl (MEM) ether. Additional protecting groups include tert-butyl, acetyl, benzyl, benzyloxycarbonyl (carbobenzyloxy, CBZ), p-methoxybenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, tert-butoxycarbonyl (BOC), trifluoroacetyl, etc. Certain protecting groups may be preferred over others for their convenience or relatively easy removal, or for their stereospecific effects in subsequent steps of the process. Additional suitable amino protecting groups are described in T.W. Greene and P.G.M. Wuts, Protecting Groups in Organic Synthesis,Fifth Edition,Wiley,New York,2014, and the references cited therein, all of which are incorporated herein by reference in their entirety.

[0057] In one embodiment, the present disclosure provides a compound of formula I

Chemical formula

Chemical formula

Chemical formula

[0058] In one embodiment, the present disclosure provides a compound of formula I

Chemical formula

Chemical formula

Chemical formula

[0059] In one embodiment, the present disclosure provides a compound of formula I

Chemical formula

Chemical formula

Chemical formula

[0060] In certain embodiments, R 1 is G 1 , OH, -NR 1c -C 1-4 alkylene-G 1 , -NR 1c -C 1-4 alkylene-N(R 1d )2, -N(R 1c )CHR 1e CO2H, -N(R 1c )CH2CO2H, and -N(R 1f )-CH2CH2-(N(CH2CO2H)CH2CH2) m -N(CH2CO2H)2, and is selected from the group consisting of R 1e is -C 1-4 alkylene-CO2H, R 1f is hydrogen or -C 1-4 alkylene-CO2H, G 1 is a 4- to 8-membered monocyclic heterocyclyl containing a first nitrogen and optionally one additional heteroatom selected from nitrogen, oxygen, and sulfur, and G 1 is bonded by the first nitrogen and is optionally substituted with 1 to 4 substituents independently selected from the group consisting of C 1-4 alkyl, C 1-4 haloalkyl, halo, cyano, OH, -OC 1-4 alkyl, and oxo, m is 0, 1, or 2.

[0061] In certain embodiments, R 1 is an amino acid moiety.

[0062] In certain embodiments, the compound of formula III is N,O-bis(trimethylsilyl)acetamide.

[0063] In certain embodiments, the organic solvent comprises DMF, DCM, or a mixture thereof.

[0064] In certain embodiments, the base comprises an organic base. In certain embodiments, the base comprises an amine base. In certain embodiments, the base comprises DIPEA.

[0065] In certain embodiments, the contacting comprises stirring at room temperature for about 24 hours.

[0066] In certain embodiments, the process further comprises reacting a payload moiety, or a salt thereof, with a compound of formula IV

Chemical formula

[0067] In certain embodiments, the organic solvent comprises DMF, DCM, or a mixture thereof.

[0068] In certain embodiments, the base comprises an organic base. In certain embodiments, the base comprises an amine base. In certain embodiments, the base comprises DIPEA.

[0069] In certain embodiments, the contacting comprises stirring at room temperature for about 1 - 2 hours.

[0070] In certain embodiments, the compound of formula I is of formula IA

Chemical formula

Chemical formula

[0071] In certain embodiments, the compound of formula I is of formula IA

Chemical formula

Chemical formula

[0072] In certain embodiments, the compound of formula IV is of formula IVA

Chemical formula

[0073] Also, the compound of formula X

Chemical formula

Chemical formula

Chemical formula

[0074] Also provided is a process for preparing a compound of formula X

Chemical formula

Chemical formula

Chemical formula

[0075] In certain embodiments, the compound of formula III is N,O-bis(trimethylsilyl)acetamide.

[0076] In certain embodiments, the organic solvent comprises DMF, DCM, or a mixture thereof.

[0077] In certain embodiments, the base comprises an organic base. In certain embodiments, the base comprises an amine base. In certain embodiments, the base comprises DIPEA.

[0078] In certain embodiments, the contacting comprises stirring at room temperature for about 24 hours.

[0079] In certain embodiments, the compound of formula X is of formula XA

Chemical formula

Chemical formula

[0080] In certain embodiments, a process for preparing a compound of formula IV, or a salt thereof, wherein R 2 and n are as defined herein, comprises contacting a compound of formula V

Chemical formula

[0081] In certain embodiments, the organic solvent comprises acetonitrile. In certain embodiments, the organic solvent comprises dry acetonitrile.

[0082] In certain embodiments, the base comprises an organic base. In certain embodiments, the base comprises an amine base. In certain embodiments, the base comprises DIPEA.

[0083] In certain embodiments, the contacting comprises stirring at room temperature.

[0084] In certain embodiments, the compound of formula V is of formula VA

Chemical formula

[0085] Also, the compound of formula I

Chemical formula

Chemical formula

[0086] Also, a process for preparing a compound of formula I [Chemical formula] (wherein R 1 is an amino acid moiety, n is 0, 1, 2, 3 or 4, each R 2 is independently C 1-4 alkyl, C 1-4 haloalkyl, and C 1-4 alkoxy, D is a payload moiety) or a salt thereof, which process comprises contacting a compound of formula X or a salt thereof with a payload moiety or a salt thereof in an organic solvent in the presence of a base. Also provided is a process. [Chemical formula] In certain embodiments, the organic solvent comprises DMF, DCM or a mixture thereof.

[0087] In certain embodiments, the base comprises an organic base. In certain embodiments, the base comprises an amine base. In certain embodiments, the base comprises DIPEA.

[0088] In certain embodiments, the contacting comprises stirring at room temperature for about 1 to 2 hours.

[0089] In certain embodiments, the compound of formula I is represented by formula IA

[0090] [Chemical formula] and the compound of formula X is represented by formula XA [Chemical formula] (wherein R 5 is hydrogen or C 1-4 alkyl).

[0091] Also, a process for preparing a composition comprising a compound of formula IV

Chemical formula

Chemical formula

[0092] In certain embodiments, the process further comprises isolating the solid formed in the aqueous product mixture.

[0093] In certain embodiments, the process further comprises grinding the solid in acetonitrile at a temperature of about 30 - about 50°C to form a ground solid.

[0094] In certain embodiments, the process further comprises isolating the ground solid.

[0095] In certain embodiments, the anhydrous organic solvent is anhydrous acetonitrile.

[0096] In certain embodiments, the base is a trialkylamine base.

[0097]

[0098] ​In certain embodiments, the base is diisopropylethylamine.

[0099] In certain embodiments, the compound of formula IV is of formula IVA

Chemical formula

Chemical formula

[0100] Also, a process for decomposing a composition comprising one or more stereoisomers of a compound of formula VI

Chemical formula

[0101] In certain embodiments, the chiral base is cinchonidine.

[0102] In certain embodiments, the contacting of step (a) is carried out in a solvent selected from acetone / water or acetone / isopropyl alcohol.

[0103] In certain embodiments, the cooling of step (b) is carried out at a temperature of about 15 °C or lower.

[0104] In certain embodiments, the cooling of step (b) is at a temperature of about 10 to about 15 °C.

[0105] In certain embodiments, the cooling of step (b) is maintained for at least about 8 hours.

[0106] In certain embodiments, the isolation of step (c) is by filtration.

[0107] In certain embodiments, the process further comprises dissolving the chiral salt of the compound of formula VI obtained from step (c) in a suitable solvent and repeating steps (b) and (c) prior to step (d).

[0108] In certain embodiments, the process further comprises dissolving the chiral salt of the compound of formula VI obtained from step (c) in a suitable solvent and repeating steps (b) and (c) 2, 3, 4, 5 or 6 times prior to step (d).

[0109] In certain embodiments, the compound of formula VI is of formula VIA

Chemical formula

[0110] Also, the compound of formula VII

Chemical formula

[0111] Also, the compound of formula VII may be represented by the formula VIIA, [ka] and the compound of formula VI is represented by formula VIA [ka] (In the formula, R 5 is hydrogen or C 1-4 Also provided herein is the process of claim 34, represented by:

[0112] Also, the compound of formula VIIB [ka] (In the formula, R 4 is hydrogen or C 1-4 is alkyl, R 5 is hydrogen or C 1-4A process for preparing an enantiomerically enriched composition comprising a compound IXB (which is alkyl) or a salt thereof,

Chemical formula

[0113] Also provided herein is a process for resolving a composition comprising one or more stereoisomers of a compound of formula VIIA

Chemical formula

[0114] In certain embodiments, the chiral base is (R)-1-amino-2-propanol. In certain embodiments, the chiral base is L-phenylalaninol. In certain embodiments, the chiral base is (S)-phenylglycinol. In certain embodiments, the chiral base is (S)-diphenyl-2-pyrrolidinemethanol.

[0115] Also provided is a compound of formula IXB

Chemical formula

Chemical formula

[0116] Also, a process for preparing an enantiomerically enriched composition containing a compound of formula VIIIB

Chemical formula

Chemical formula

[0117] Also, a process for preparing an enantiomerically enriched composition containing a compound of formula VIIB

Chemical formula

Chem.

Chem.

Chem.

[0118] Also provided herein is a process for preparing a composition enriched enantiomerically in a compound of formula VB

Chem.

Chem.

[0119] In certain embodiments, isomerization comprises exposing a compound of formula VA to UV light.

[0120] In certain embodiments, R 4 is C 1-4 alkyl, the process further comprises a hydrolysis step to convert R 4 to hydrogen.

[0121] Also provided herein is a process for preparing an enantiomerically enriched composition comprising a compound of formula IVB

Chemical formula

Chemical formula

[0122] In certain embodiments of any of the formulas described herein, R 1 is a glycine moiety. In certain embodiments of any of the formulas described herein, R 1 is glycine.

[0123] In certain embodiments of any of the formulas described herein, n is 1.

[0124] In certain embodiments of any of the formulas described herein, R 2 is C 1-4 alkyl. In certain embodiments of any of the formulas described herein, R 2 is methyl.

[0125] In certain embodiments of any of the formulas described herein, R5 is methyl.

[0126] Amino acid moiety The term "amino acid" refers to both natural and non-natural amino acids. In certain embodiments, the amino acid moiety is a natural amino acid. Natural amino acids include the 20 proteinogenic amino acids that are directly encoded by the triplet codons of the genetic code and include alanine (ala, A), arginine (arg, R), asparagine (asn, N), aspartic acid (asp, D), cysteine (cys, C), glutamine (gln, Q), glutamic acid (glu, E), glycine (gly, G), histidine (his, H), isoleucine (ile, I), leucine (leu, L), lysine (lys, K), methionine (met, M), phenylalanine (phe, F), proline (pro, P), serine (ser, S), threonine (thr, T), tryptophan (trp, W), tyrosine (tyr, Y), and valine (val, V).

[0127] The amino acid moiety may also include non-natural amino acids. In its broadest sense, the term "amino acid moiety" includes any organic compound having amine (-NH2) and carboxylic acid (-CO2H) functional groups.

[0128] In certain embodiments, the amino acid moiety is -NR 1c -C 1-4 alkylene, - optionally substituted heterocyclyl, -NR 1c -C 1-4 alkylene-N(R 1d )2, -N(R 1c )CHR 1e CO2H, -N(R 1c )-C 1-6 alkylene-CO2H, -N(R 1f )-C 2-4 alkylene-(N(C 1-4 alkylene-CO2H)-C 2-4 alkylene) m -N(C 1-4 alkylene-CO2H)2, -N(R 1c )CHR 1e C(O)OC1-6 alkyl, -N(R 1c )-C 1-6 alkylene-C(O)OC 1-6 alkyl, and -N(R 1f )-C 2-4 alkylene-(N(C 1-4 alkylene-C(O)OC 1-6 alkyl)-C 2-4 alkylene) m -N(C 1-4 alkylene-C(O)OC 1-6 alkyl)2, wherein R 1c and R 1d are each independently hydrogen or C 1-4 alkyl, R 1e is -C 1-4 alkylene-CO2H, -C 1-4 alkylene-CONH2, or -C 1-4 alkylene-OH, R 1f is hydrogen, -C 1-6 alkyl, or -C 1-4 alkylene-CO2H, m is 0, 1, 2, or 3.

[0129] In certain embodiments, the amino acid moiety is glycine. In certain embodiments, the amino acid moiety is alanine.

[0130] Payload As used herein, the "payload moiety" refers to the portion of the payload D remaining after subtracting a nucleophilic group such as NH, NC 1-4 alkyl, O, or S that binds to the linker, or an electrophilic group such as C(O) that binds to the linker, i.e., the remaining portion of the payload. The term "payload" generally refers to an agent for delivery to a target site of interest and includes, but is not limited to, therapeutic agents, diagnostic agents, target agents, etc.

[0131] In some embodiments, the payload is a therapeutic agent such as an antibiotic, an antifungal agent, an antiviral agent, an anticancer agent, a cardiovascular agent, a CNS agent, an anti-inflammatory / anti-arthritis agent, an anti-TB / anti-Hansen's disease agent, an antihistamine / respiratory disease agent, a corticosteroid agent, an immunosuppressive agent, or an anti-ulcer agent. Specific therapeutic agents include paclitaxel, doxorubicin, daunorubicin, etoposide, irinotecan, SN-38, docetaxel, gemcitabine, podophyllotoxin, carmustine, ixabepilone, patupilone, cyclosporin A, rapamycin, amphotericin, vancomycin, daptomycin, doxycycline, ceftriaxone, trimethoprim, sulfamethoxazole, acyclovir, nystatin, amphotericin B, flucytosine, emtricitabine, gentamicin, colistin, L-dopa, oseltamivir, cephalexin, 5-aminolevulinic acid, cysteine, celecoxib, and nimodipine.

[0132] In certain embodiments, the payload moiety is an anthracycline moiety, an auristatin moiety, a glycopeptide antibiotic moiety, or a lipopeptide antibiotic moiety.

[0133] In certain embodiments, the payload moiety is a doxorubicin moiety, a daunorubicin moiety, a monomethyl auristatin E moiety, a vancomycin moiety, or a daptomycin moiety.

[0134] In certain embodiments, D is a therapeutic agent such as an antibiotic, an antifungal agent, an antiviral agent, an anticancer agent, a cardiovascular agent, a CNS agent, an anti-inflammatory / anti-arthritis agent, an anti-TB / anti-Hansen's disease agent, an antihistamine / respiratory disorder agent, a corticosteroid agent, an immunosuppressive agent, or an anti-ulcer agent.

[0135] In certain embodiments, D is an antibiotic. Suitable antibiotics include, but are not limited to, β-lactams such as penicillins and cephalosporins, such as thienamycin, monobactams, β-lactamase inhibitors and methoxypenicillin; aminoglycosides such as streptomycin, gentamicin, kanamycin, tobramycin, amikacin, neomycin, ribostamycin, micronomicin and astromicin; tetracyclines such as tetracycline, oxytetracycline, chlortetracycline and doxycycline; chloramphenicols such as chloramphenicol and thiamphenicol; macrolides such as erythromycin, albomycin, erythromycin estolate, erythromycin ethylsuccinate, azithromycin, acetylspiramycin, midecamycin and josamycin; other antibiotics acting on Gram-positive bacteria such as lincomycin, clindamycin, vancomycin and bacitracin; other antibiotics acting on Gram bacteria such as polymyxin, fosfomycin, ciramycin, cycloserine and rifampicin; antifungal antibiotics such as griseofulvin; anticancer antibiotics such as mitomycin, actinomycin D, bleomycin and adriamycin; and immunosuppressive antibiotics such as cyclosporine.

[0136] In certain embodiments, D is an anticancer agent, an anticoagulant, a microbial immunosuppressant, or an anti-restenosis agent. The anticancer agent can be one or more selected from methotrexate, purines, pyrimidines, plant alkaloids, epothilones, tryptolide compounds, antibiotics (especially actinomycin D), hormones and antibodies. Among the plant alkaloids, paclitaxel, doxorubicin, maytansine, auristatin, calicheamicin, duocarmycin, tubulysin and camptothecin can be particularly mentioned. The anticoagulant can be one or more selected from heparin, aspirin, hirudin, colchicine, and platelet GPIIb / IIIa receptor antagonists.

[0137] The platelet GPIIb / IIIa receptor antagonist can be one or more selected from tirofiban, abciximab, and eptifibatide. The microbial immunosuppressant can be one or more selected from cyclosporin A, tacrolimus and its analogs, despergualin, mycophenolate ester, rapamycin and its derivatives, the FR-900520 substance derived from Streptomyces strain, the FR-900523 substance derived from Streptomyces strain, daclizumab, pentamidine, kangremycin C, spergualin, prodigiosin-25C, tranilast, myriocin, cyclosporin C, brequinar, mycophenolic acid, brefeldin A, and ketosteroid. The anti-restenosis agent can be one or more selected from batimastat, metalloproteinase inhibitor, 17β-estradiol, NO donor, 2-chlorodeoxyadenosine, 2-deoxycoformycin, fingolimod, sodium mycophenolate, ISATX247 (a cyclosporin A derivative), elsubrole, daclizumab, basiliximab, antithymocyte globulin, everolimus, methotrexate, neoral, cyclophosphamide, brequinar sodium, leflunomide, and mizoribine.

[0138] In certain embodiments, D is an anti-cancer agent. Exemplary anti-cancer agents include, but are not limited to, abiraterone acetate, abitrexate (methotrexate), abraxane (paclitaxel albumin-stabilized nanoparticle formulation), ABVD, ABVE, ABVE-PC, AC, AC-T, adcetris (brentuximab vedotin), ADE, ado-trastuzumab emtansine, adriamycin (doxorubicin hydrochloride), Adrucil (fluorouracil), afatinib dimaleate, Afinitor (everolimus), Aldara (imiquimod), aldesleukin, alemtuzumab, Alimta (pemetrexed disodium), Aloxi (palonosetron hydrochloride), Ambochlorin (chlorambucil), Amboclorin (chlorambucil), amboclorin (chlorambucil), aminolevulinic acid, anastrozole, aprepitant, Aredia (sodium pamidronate), Arimidex (anastrozole), Aromasin (exemestane), Arranon (nelarabine), arsenic trioxide, Arzerra (ofatumumab), asparaginase Erwinia chrysanthemi, Avastin (bevacizumab), axitinib, azacitidine, BEACOPP, bendamustine hydrochloride, BEP, bevacizumab, bexarotene, Bexxar (tositumomab and I131I tositumomab, bicalutamide, bleomycin, bortezomib, Bosulif (bosutinib), bosutinib, brentuximab vedotin, busulfan, Busulfex (busulfan), cabazitaxel, cabozantinib-S-malate, CAF, Campath (alemtuzumab), Camptosar (irinotecan hydrochloride), capecitabine, CAPOX, carboplatin, carboplatin-taxol, carfilzomib, Casodex (bicalutamide), CeeNU (lomustine), Cerubidine (daunorubicin hydrochloride), Cervarix (recombinant HPV bivalent vaccine), cetuximab, chlorambucil, chlorambucil-prednisone, CHOP, cisplatin, Clafen (cyclophosphamide), clofarabine, Clolar (clofarabine), CMF, Cometriq (cabozantinib-S-malate), COPP, COPP-ABV, Cosmegen (dactinomycin), crizotinib, CVP, cyclophosphamide, Cyfos (ifosfamide), cytarabine, cytarabine, liposome, Cytosar-U (cytarabine), Cytoxan (cyclophosphamide), dabrafenib, dacarbazine, Dacogen (decitabine), dactinomycin, dasatinib, daunorubicin hydrochloride, decitabine, degarelix, denileukin diftitox, denosumab, DepoCyt (liposomal cytarabine), DepoFoam (liposomal cytarabine), dexrazoxane hydrochloride, docetaxel, Doxil (doxorubicin hydrochloride liposome), doxorubicin hydrochloride, doxorubicin hydrochloride liposome, Dox-SL (doxorubicin hydrochloride liposome), DTIC-Dome (dacarbazine), Efudex (fluorouracil), Elitek (rasburicase), Ellence (epirubicin hydrochloride), Eloxatin (oxaliplatin), eltrombopag olamine, Emend (aprepitant), enzalutamide, epirubicin hydrochloride, EPOCH, Erbitux (cetuximab), eribulin mesylate, Erivedge (vismodegib), erlotinib hydrochloride, Erwinaze (asparaginase Erwiniachrysanthemi), Etopophos (etoposide phosphate), etoposide, etoposide phosphate, Evacet (doxorubicin hydrochloride liposome), everolimus, Evista (raloxifene hydrochloride), exemestane, Fareston (toremifene), Faslodex (fulvestrant), FEC, Femara (letrozole), filgrastim, Fludara (fludarabine phosphate), fludarabine phosphate, Fluoroplex (fluorouracil), fluorouracil, Folex (methotrexate), Folex PFS (methotrexate), folfiri, folfiri - bevacizumab, folfiri - cetuximab, folfirinox, folfox (leucovorin, fluorouracil, oxaliplatin), Folotyn (pralatrexate), FU - LV, fulvestrant, Gardasil (recombinant quadrivalent HPV vaccine), Gazyva (obinutuzumab), gefitinib, gemcitabine hydrochloride, gemcitabine - cisplatin, gemcitabine - oxaliplatin, gemtuzumab ozogamicin, Gemzar (gemcitabine hydrochloride), Gilotrif (afatinib dimaleate), Gleevec (imatinib mesylate), glucarpidase, goserelin acetate, Halaven (eribulin mesylate), Herceptin (trastuzumab), bivalent HPV vaccine (recombinant), quadrivalent HPV vaccine (recombinant), Hycamtin (topotecan hydrochloride), Hyper - CVAD, ibritumomab tiuxetan, ibrutinib, ICE, Iclusig (ponatinib hydrochloride), Ifex (ifosfamide), ifosfamide, ifosfamidem (ifosfamide), imatinib mesylate, Imbruvica (ibrutinib), imiquimod, Inlyta (axitinib), IntronA (Recombinant Interferon Alpha-2b), Iodine 131 Tositumomab and Tositumomab, Ipilimumab, Iressa (Gefitinib), Irinotecan Hydrochloride, Istodax (Romidepsin), Ixabepilone, Ixempra (Ixabepilone), Jakafi (Ruxolitinib Phosphate), Jevtana (Cabazitaxel), Kadcyla (Ado-Trastuzumab Emtansine), Tamoxifen (Raloxifene Hydrochloride), Kepivance (Palifermin), Kyprolis (Carfilzomib), Lapatinib Ditosylate, Lenalidomide, Letrozole, Leucovorin Calcium, Leukeran (Chlorambucil), Leuprolide Acetate, Levulan (Aminolevulinic Acid), Linfolizin (Chlorambucil), LipoDox (Doxorubicin Hydrochloride Liposome), Liposomal Cytarabine, Lomustine, Lupron (Leuprolide Acetate), Lupron Depot (Leuprolide Acetate), Lupron Depot-Ped (Leuprolide Acetate), Lupron Depot-3 Month (Leuprolide Acetate), Lupron Depot-4 Month (Leuprolide Acetate), Marqibo (Vincristine Sulfate Liposome), Matulane (Procarbazine Hydrochloride), Mechlorethamine Hydrochloride, Megace (Megestrol Acetate), Megestrol Acetate, Mekinist (Trametinib), Mercaptopurine, Mesna, Mesnex (Mesna), Metazolastone (Temozolomide), Methotrexate, Methotrexate LPF (Methotrexate), Mexate (Methotrexate), Mexate-AQ (Methotrexate), Mitomycin C, Mitozytrex (Mitomycin C), MOPP, Mozobil (Plerixafor), Mustargen (Mechlorethamine Hydrochloride), Mutamycin (Mitomycin C), Myleran (Busulfan), Mylosar (Azacitidine), Mylotarg (Gemtuzumab Ozogamicin), Nanoparticle Paclitaxel (Paclitaxel Albumin-Stabilized Nanoparticle Formulation), Navelbine (Vinorelbine Tartrate), Nelarabine, Neosar (Cyclophosphamide), Neupogen (Filgrastim), Nexavar (Sorafenib Tosylate), Nilotinib, Nolvadex (Tamoxifen Citrate), Nplate (Romiplostim), Obinutuzumab, Ofatumumab, Omacetaxine Mepesuccinate, Oncaspar (Pegaspargase), Ontak (Denileukin Diftitox), OEPA, OPPA, Oxaliplatin, Paclitaxel, Paclitaxel Albumin-Stabilized Nanoparticle Formulation, Palifermin, Palonosetron Hydrochloride, Pamidronate Disodium, Panitumumab, Paraplat (Carboplatin), Paraplatin (Carboplatin), Pazopanib Hydrochloride, Pegaspargase, Peginterferon Alfa-2b, PEG-Intron (Peginterferon Alfa-2b), Pemetrexed Disodium, Perjeta (Pertuzumab), Pertuzumab, Platinol (Cisplatin), Platinol-AQ (Cisplatin), Plerixafor, Pomalidomide, Pomalyst (Pomalidomide), Ponatinib Hydrochloride, Pralatrexate, Prednisone, Procarbazine Hydrochloride, Proleukin (Aldesleukin), Prolia (Denosumab),Promacta (eltrombopag olamine), Provenge (sipuleucel-T), Purinethol (mercaptopurine), radium 223 dichloride, raloxifene hydrochloride, rasburicase, R-CHOP, R-CVP, recombinant HPV bivalent vaccine, recombinant HPV quadrivalent vaccine, recombinant interferon alpha-2b, regorafenib, Revlimid (lenalidomide), Rheumatrex (methotrexate), Rituxan (rituximab), rituximab, romidepsin, romiplostim, rubidomycin (daunorubicin hydrochloride), loxicitinib phosphate, Sclerosol intrapleural aerosol (talc), sipuleucel-T, sorafenib tosylate, Sprycel (dasatinib), Stanford V, sterilized talc powder (talc), Steritalc (talc), Stivarga (regorafenib), sunitinib malate, Sutent (sunitinib malate), Sylatron (peginterferon alpha-2b), Synovir (thalidomide), Synribo (omacetaxine mepesuccinate), Tafinlar (dabrafenib), talc, tamoxifen citrate, Tarabine PFS (cytarabine), Tarceva (erlotinib hydrochloride), Targretin (bexarotene), Tasigna (nilotinib), Taxol (paclitaxel), Taxotere (docetaxel), Temodar (temozolomide), temozolomide, temsirolimus, thalidomide, Thalomid (thalidomide), Toposar (etoposide), topotecan hydrochloride, toremifene, Torisel (temsirolimus), tositumomab and I131 iodine tositumomab, Totect (dexrazoxane hydrochloride), trametinib, trastuzumab, Treanda (bendamustine hydrochloride), Trisenox (arsenic trioxide), Tykerb (lapatinib ditosylate), vandetanib, VAMP, Vectibix (panitumumab), VeIP, Velban (vincristine sulfate), Velcade (bortezomib), Velsar (vincristine sulfate), vemurafenib, VePesid (etoposide), Viadur (leuprolide acetate), Vidaza (azacitidine), vincristine sulfateVincasar PFS (Vincristine Sulfate), Vincristine Sulfate, Vincristine Sulfate Liposome, Vinorelbine Tartrate, Bismodigib, Voraxaze (Glucarpidase), Vorinostat, Votrient (Pazopanib Hydrochloride), Wellcovorin (Calcium Leucovorin), Xalkori (Crizotinib), Xeloda (Capecitabine), Xelox, Xgeva (Denosumab), Xofigo (Radium 223 Dichloride), Xtandi (Enzalutamide), Yervoy (Ipilimumab), Zaltrap (Ziv-Aflibercept), Zelboraf (Vemurafenib), Z, evalin (Ibritumomab Tiuxetan), Zinecard (Dexrazoxane Hydrochloride), Ziv-Aflibercept, Zoladex (Goserelin Acetate), Zoledronic Acid, Zolinza (Vorinostat), Zometa (Zoledronic Acid) and Zytiga (Abiraterone Acetate) are included.

[0139] In certain embodiments, D is a PBD dimer, calicheamicin, esperamicin, tubulysin B, lysocine, drastatin, didemnin B, camptothecin, CBI, temsirolimus, actinomycin D, epothilone B, taxol, cryptophycin, SN38, berkeleycin, bruceantin, DAVLBH, DM1, philanthotoxin, Alimta, T2 toxin, MMC, vantanib, vinorelbine, brefeldin, sunitinib, daunomycin, semaxanib, Tarceva, Iressa, irinotecan, LY-541503, geldanamycin, gemcitabine, methotrexate, Gleevec, topotecan, bleomycin, doxorubicin, cisplatin, nitrogen mustard, etoposide, or 5-FU.

[0140] In certain embodiments, D is an anthracycline. In certain embodiments, D is a taxane. In certain embodiments, D is gemcitabine. In certain embodiments, D is doxorubicin. In certain embodiments, D is docetaxel. In certain embodiments, D is SN38. In certain embodiments, D is monomethyl auristatin E. In certain embodiments, D is dexamethasone. In certain embodiments, D is celecoxib. In certain embodiments, D is gentamicin.

[0141] In certain embodiments, D is an agent that enhances intracellular penetration. For example, D can be a functionalized keto acid, 6-oxo-6-phenylhexanoic acid, 8-oxo-8-phenyloctanoic acid, 8-(2,5-dichlorophenyl)-8-oxooctanoic acid, a functionalized keto ester or aldehyde, a modified amino acid, modified amino acids, N-[8-(2-hydroxybenzoyl)aminooctanoic acid, N-[8-(2-hydroxybenzoyl)aminodecanoic acid, N-(5-chlorosalicylic acid)-8-aminocaprylic acid, N-[4-(4-chloro-2-hydroxybenzoyl)amino]butanoic acid, 2-ethylhexyl 2-hydroxybenzoate, 5-cyclohexyl-5-oxovaleric acid, 6-cyclohexyl-6-oxohexanoic acid, 7-cyclohexyl-7-oxoheptanoic acid, 8-cyclohexyl-8-oxooctanoic acid, 4-cyclopentyl-4-oxobutyric acid, 5-cyclopentyl-5-oxovaleric acid, 6-cyclopentyl-6-oxohexanoic acid, 7-cyclopentyl-7-oxoheptanoic acid, 8-cyclopentyl-8-oxooctanoic acid, 4-cyclobutyl-4-oxobutyric acid, 5-cyclobutyl-5-oxovaleric acid, 6-cyclobutyl-6-oxohexanoic acid, 7-cyclobutyl-7-oxoheptanoic acid, 8-cyclobutyl-8-oxooctanoic acid, 4-cyclopropyl-4-oxobutyric acid, 5-cyclopropyl-5-oxovaleric acid, 6-cyclopropyl-6-oxohexanoic acid, 7-cyclopropyl-7-oxoheptanoic acid, 8-cyclopropyl-8-oxooctanoic acid, 8-[(3-methylcyclohexyl)oxy]octanoic acid, 7-[(3-methylcyclohexyl)oxy]heptanoic acid, 6-[(3-methylcyclohexyl)oxy]hexanoic acid, 5-[(3-methylcyclohexyl)oxy]pentanoic acid, 4-[(3-methylcyclohexyl)oxy]butanoic acid, 3-[(3-methylcyclohexyl)oxy]propanoic acid, octyl salicylate, diketopiperazine, saponin, acylcarnitine, alkanoylcholine, taurodihydrofusidate, sulfoxide, oxazolidinone, pyrrolidone, an alcohol or alkanol, benzoic acid, glycol, surfactant, terpene, any functionally effective salt of any of the above, any derivative of any of the above, or a combination thereof.

[0142] 3. Compounds In certain embodiments, the present disclosure provides intermediate compounds that are useful in the processes described herein. Accordingly, in one embodiment, a compound selected from Table 1 or a salt thereof is provided. In another embodiment, an enantiomerically enriched composition comprising a compound selected from Table 1 or a salt thereof is provided.

[0143] In Table 1, and as used throughout, it is understood that straight thick or dashed bonds are used to indicate relative stereochemistry, and wedge-shaped thick or dashed bonds are used to indicate absolute stereochemistry. When a composition is identified as being enantiomerically enriched, the composition is intended to comprise a single enantiomer of greater than 50% or at least about 55% or at least about 60% or at least about 65% or at least about 70% or at least about 75% or at least about 80% or at least about 85% or at least about 90% or at least about 95% or at least about 97% or about 99% ee.

Table 1-1

Table 1-2

[0144] It should also be understood that the specific features described herein in the context of separate embodiments may be provided in combination in a single embodiment. Conversely, various features described herein in the context of a single embodiment for brevity may be provided separately or in any suitable sub-combination. All combinations of embodiments regarding chemical groups represented by variables included in Formula I are included herein as if every such combination was individually and explicitly recited, provided that such combinations include compounds that result in stable compounds (i.e., compounds that can be isolated, characterized, and tested for biological activity).

Example

[0145] The compounds of the present disclosure can be prepared using the methods disclosed herein, variations of those routines that will be apparent in light of the disclosure herein, and methods known in the art. In addition to the teachings herein, conventional well-known synthetic methods can be used. The synthesis of the compounds described herein can be accomplished as described in the following examples. When available, reagents can be purchased commercially, for example, from Sigma Aldrich or other chemical suppliers. Unless otherwise indicated, the starting materials for the following reactions are available from commercial sources.

[0146] Example 1: Chiral Resolution of (Z)-1-Methylcycloocta-4-ene-1-carboxylic Acid In previous reports, compound IV was formed only on a small scale as a racemate, whereas in the following procedure, a single enantiomer of compound IV with ≥97% ee is produced on a kilogram scale from a racemic starting material (Rossin, R. et al. Bioconjugate Chem. 2016, 1697 - 1706).

Chemical formula

[0147] (Z)-1-Methylcycloocta-4-ene-1-carboxylic acid (34.3 kg) was dissolved in EA (1355 kg). A solution of cinchonidine (60 kg) in DCM (460 kg) was added at 35 - 40 °C. The mixture was stirred at 45 °C for 4 hours and then cooled to 12 °C over an additional 8 hours. The resulting suspension was filtered. The recovered cake needed to be further purified by recrystallization.

[0148] First recrystallization: The salt (220 g) was completely dissolved in isopropanol (1 L) and acetone (5 L) at 60 °C. The mixture was maintained at 10 - 15 °C overnight. It was filtered and dried to obtain 148 g of the product with 28.0% ee.

[0149] Second recrystallization: Salt (148 g) was completely dissolved in isopropanol (750 mL) and acetone (3850 mL) at 60 °C. The mixture was maintained at 10 - 15 °C overnight. It was filtered and dried to obtain 85.2 g of the product with 54.0% ee. The mother liquor was concentrated to obtain 62.8 g of a solid.

[0150] Third recrystallization: Salt (85.2 g) was completely dissolved in isopropanol (420 mL) and acetone (2100 mL) at 60 °C. The mixture was maintained at 10 - 15 °C overnight. It was filtered and dried to obtain 66.0 g of the product with 74.3% ee. The mother liquor was concentrated to obtain 19.0 g of a solid.

[0151] Fourth recrystallization: Salt (66.0 g) was completely dissolved in isopropanol (330 mL) and acetone (1650 mL) at 60 °C. The mixture was maintained at 10 - 15 °C overnight. It was filtered and dried to obtain 42.7 g of the product with 83.4% ee. The mother liquor was concentrated to obtain 13.3 g of a solid.

[0152] Fifth recrystallization: Salt (42.7 g) was completely dissolved in isopropanol (210 mL) and acetone (1050 mL) at 60 °C. The mixture was maintained at 10 - 15 °C overnight. It was filtered and dried to obtain 31.8 g of the product with 91.0% ee. The mother liquor was concentrated to obtain 10.9 g of a solid.

[0153] Sixth recrystallization: Salt (31.8 g) was completely dissolved in isopropanol (160 mL) and acetone (800 mL) at 60 °C. The mixture was maintained at 10 - 15 °C overnight. It was filtered and dried to obtain 26.2 g of the product with 95.3% ee. The mother liquor was concentrated to obtain 5.6 g of a solid.

[0154] The concentrates of the mother liquor (ee > 0%) were combined and purified by several recrystallizations to obtain more than 4 single isomers.

[0155] The solid salt (a single isomer of (Z)-1-methylcycloocta-4-ene-1-carboxylic acid containing cinchonidine, 6 kg) was mixed with water (35.0 kg). The mixture was added to an HCl solution (2.0 kg of 12N concentrated hydrochloric acid diluted with 10.0 kg of water) at 20 - 30 °C to adjust the pH to 1. The resulting mixture was washed with hexane (3 × 15.0 kg). The combined organic phases were washed with brine (10 kg). The organic phase was concentrated at 35 - 55 °C to obtain the single isomer of the title compound as an oil.

Table 2

[0156] Upgrade of %ee after desalting: - The salt converted to the free acid of (Z)-1-methylcycloocta-4-ene-1-carboxylic acid by the addition of -HCl - Dissolve (Z)-1-methylcycloocta-4-ene-1-carboxylic acid and add seeds of the desired stereoisomer to induce crystallization - Precipitation is observed, but analysis shows no difference in %ee between the solid and the supernatant - It is suggested that the racemate may exist as a solid solution, making concentration in the acid form impossible

[0157] Increase in the purity of the starting material: - A 47% low-purity racemate was spiked with pure, concentrated (Z)-1-methylcycloocta-4-ene-1-carboxylic acid (33%ee). - Spiking with impurities did not affect the relative solubility of the desired and undesired enantiomers - Therefore, no significant improvement in %ee was observed when using pure (Z)-1-methylcycloocta-4-ene-1-carboxylic acid compared to impure (Z)-1-methylcycloocta-4-ene-1-carboxylic acid for the resolution process

[0158] Dependence of the relative solubility of the desired / undesired enantiomers on %ee: - The solubility of the desired and undesired enantiomers was measured in samples of various degrees of enantiomeric enrichment in the range of 0 - 88% ee. - In the case of a racemate, the solubility of the undesired enantiomer exceeds that of the desired enantiomer. - However, when 46% ee is reached, the solubility trend reverses, and the solubility of the desired enantiomer salt exceeds that of the undesired enantiomer salt. - This switch complicates the development of a high - yield chiral resolution process that reaches ≥97% ee starting from the racemate.

[0159] Other solvents were screened, and the results are shown below.

Table 3

[0160] Example 2: Large - scale synthesis of enantiomerically enriched cis - (Z) - 6 - hydroxy - 1 - methylcycloocta - 4 - en - 1 - carboxylic acid A process for producing the single enantiomer (≥97% ee) cis - (Z) - 6 - hydroxy - 1 - methylcycloocta - 4 - en - 1 - carboxylic acid on a kilogram scale from a racemic starting material. The literature reports the synthesis of 17.5 g of racemic cis - (Z) - 6 - hydroxy - 1 - methylcycloocta - 4 - en - 1 - carboxylic acid. (Rossin, R. et al. Bioconjugate Chem. 2016, 1697 - 1706).

Chemical formula

[0161] Compound 4 (34.3 kg) was dissolved in EA (1355 kg). A solution of cinchonidine (60 kg) in DCM (460 kg) was added at 35 - 40 °C. The mixture was stirred at 45 °C for 4 hours and then further cooled to 12 °C over 8 hours. The resulting suspension was filtered. The recovered cake needs to be further purified by recrystallization.

[0162] First recrystallization: Salt (220 g) was completely dissolved in isopropanol (1 L) and acetone (5 L) at 60 °C. The mixture was maintained at 10 - 15 °C overnight. It was filtered and dried to obtain 148 g of the product with 28.0% ee.

[0163] Second recrystallization: Salt (148 g) was completely dissolved in isopropanol (750 mL) and acetone (3850 mL) at 60 °C. The mixture was maintained at 10 - 15 °C overnight. It was filtered and dried to obtain 85.2 g of the product with 54.0% ee. The mother liquor was concentrated to obtain 62.8 g of a solid.

[0164] Third recrystallization: Salt (85.2 g) was completely dissolved in isopropanol (420 mL) and acetone (2100 mL) at 60 °C. The mixture was maintained at 10 - 15 °C overnight. It was filtered and dried to obtain 66.0 g of the product with 74.3% ee. The mother liquor was concentrated to obtain 19.0 g of a solid.

[0165] Fourth recrystallization: Salt (66.0 g) was completely dissolved in isopropanol (330 mL) and acetone (1650 mL) at 60 °C. The mixture was maintained at 10 - 15 °C overnight. It was filtered and dried to obtain 42.7 g of the product with 83.4% ee. The mother liquor was concentrated to obtain 13.3 g of a solid.

[0166] Fifth recrystallization: Salt (42.7 g) was completely dissolved in isopropanol (210 mL) and acetone (1050 mL) at 60 °C. The mixture was maintained at 10 - 15 °C overnight. It was filtered and dried to obtain 31.8 g of the product with 91.0% ee. The mother liquor was concentrated to obtain 10.9 g of a solid.

[0167] Sixth recrystallization: Salt (31.8 g) was completely dissolved in isopropanol (160 mL) and acetone (800 mL) at 60 °C. The mixture was maintained at 10 - 15 °C overnight. It was filtered and dried to obtain 26.2 g of the product with 95.3% ee. The mother liquor was concentrated to obtain 5.6 g of a solid.

[0168] The concentrates of the mother liquor (ee > 0%) were combined and purified by several recrystallizations to obtain more single isomers of (Z)-1-methylcycloocta-4-ene-1-carboxylic acid.

[0169] The solid salt (single isomer of (Z)-1-methylcycloocta-4-ene-1-carboxylic acid containing cinchonidine, 6 kg) was mixed with water (35.0 kg). The mixture was added to an HCl solution (2.0 kg of 12N concentrated hydrochloric acid diluted with 10.0 kg of water) at 20 - 30 °C to adjust the pH to 1. The resulting mixture was washed with hexane (3 × 15.0 kg). The combined organic phases were washed with brine (10 kg). The organic phase was concentrated at 35 - 55 °C to obtain the single isomer of (Z)-1-methylcycloocta-4-ene-1-carboxylic acid as an oil.

[0170] The product (2.8 kg) was taken in a mixture of DCM (22.2 kg) and water (16.7 kg), and NaHCO3 (4.8 kg) was added. The reaction mixture was cooled to 0 - 5 °C, and a mixture of KI (8.2 kg) and iodine (8.4 kg) was added little by little. The reaction was stirred at room temperature for 2 hours and then sampled for GC. When the starting material was 2.0a% or less by GC, the reaction mixture was slowly quenched with sodium bisulfite (3.4 kg of sodium bisulfite in 16.7 kg of water) until a clear solution appeared. Both layers were separated, and the aqueous layer was extracted with DCM (22.2 kg). The combined organic layers were washed with water (8.4 kg), dried over Na2SO4 (1.7 kg), and concentrated enantioselectively by rotary evaporation to obtain 5-iodo-1-methyl-7-oxabicyclo[4.2.2]decane-8-one (quantitative), which was used in the next step without further purification.

[0171] The obtained product (4.8 kg) was dissolved in toluene (21.3 kg), and then DBU (2.9 kg) was added. The mixture was left at 25 - 30 °C for 12 hours and then heated under reflux for 4 hours, at which point GC showed complete conversion (5-iodo-1-methyl-7-oxabicyclo[4.2.2]decane-8-one <3a%). After cooling, the reaction mixture was washed with water (6.4 kg). The aqueous phase was extracted with toluene (10.7 kg). The organic phase was dried over Na2SO4 (2.9 kg) and then concentrated to a colorless oil (yield 94%).

[0172] (Z)-1-Methyl-7-oxabicyclo[4.2.2]dec-4-en-8-one (2.66 kg) was mixed with methanol (12.8 kg), KHCO3 (16.0 kg) and water (0.03 kg). The mixture was held at 28 °C for 24 hours and monitored by HPLC. The reaction was considered complete when NMT of the starting material was 26.0%. It was filtered and the cake was washed with methanol. The filtrate was concentrated at 35 - 55 °C, and then EA (20 kg) and water (12.58 kg) were added. The pH value of the mixture was adjusted to 2 - 3 with 2N HCl solution. The layers were separated and the aqueous phase was washed with EA (4 × 8.0 kg). The combined organic phases were washed with brine (17.2 kg), dried over Na2SO4 (1.3 kg) and then concentrated at 35 - 55 °C. The residue was purified by chromatography using hexane and EA (50:1) as the eluent to obtain the pure title product as a colorless oil. (Note: The starting material can be recycled and the mixed fractions can also be purified again to provide more product.)

[0173] Example 3: Synthesis of Enantiomerically Enriched 2,5-Dioxopyrrolidin-1-yl cis-(E)-6-((((2,5-Dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-1-methylcycloocta-4-ene-1-carboxylate from cis-(E)-6-Hydroxy-1-methylcycloocta-4-ene-1-carboxylic Acid A process for robustly synthesizing high-purity 2,5-dioxopyrrolidin-1-yl cis-(E)-6-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-1-methylcycloocta-4-ene-1-carboxylate from the TCO starting material cis-(E)-6-hydroxy-1-methylcycloocta-4-ene-1-carboxylic acid in 75% yield on a 100-gram scale without using chromatography. The reference reports the synthesis of 400 mg of 2,5-dioxopyrrolidin-1-yl cis-(E)-6-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-1-methylcycloocta-4-ene-1-carboxylate in 46% yield, which requires purification by silica gel chromatography (Rossin, R. et al. Bioconjugate Chem. 2016, 1697-1706).

Chem.

[0174] A mixture of cis-(E)-6-hydroxy-1-methylcycloocta-4-ene-1-carboxylic acid (1 equivalent), N,N'-disuccinimidyl carbonate (DSC) (4.3 equivalents), and DIPEA (7.4 equivalents) in dry acetonitrile (20 volumes) is stirred at 22-25 °C until the intermediate 2,5-dioxopyrrolidin-1-yl cis-(E)-6-hydroxy-1-methylcycloocta-4-ene-1-carboxylate is less than 0.5% AUC by UPLC (7-9 hours). The resulting suspension is added to deionized water (50 volumes) at room temperature, and the resulting mixture is stirred for about 15 minutes. The resulting solid suspension is filtered, washed with deionized water (3 × 2 volumes), and dried on the filter under vacuum for about 1 hour.

[0175] The solid crude product 2,5-dioxopyrrolidin-1-yl cis-(E)-6-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-1-methylcycloocta-4-ene-1-carboxylate is suspended in acetonitrile (about 2 volumes) and mixed at 35 - 45 °C for about 1 hour. The mixture is cooled to about 15 °C and filtered. The cake is washed with acetonitrile (2 × 1 volume) and dried on the filter under vacuum for about 60 minutes to obtain enantiomerically enriched 2,5-dioxopyrrolidin-1-yl cis-(E)-6-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-1-methylcycloocta-4-ene-1-carboxylate as a white to off-white crystalline solid with an AUC purity of about 99% by UPLC at 214 nm in an isolated yield of about 74 - 80%.

[0176] From 61.8 g of cis-(E)-6-hydroxy-1-methylcycloocta-4-ene-1-carboxylic acid, 106.0 g of 2,5-dioxopyrrolidin-1-yl cis-(E)-6-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-1-methylcycloocta-4-ene-1-carboxylate was obtained with an AUC purity of 98.6% and an isolated yield of 75.4%.

Table 4

[0177] Example 4: Chiral Resolution of Compound VIIC

Chemical Structure

[0178] Example 5: Chiral Resolution of (Z)-6-Hydroxy-1-methylcycloocta-4-ene-1-carboxylic Acid The following example shows the chiral resolution of (Z)-6-hydroxy-1-methylcycloocta-4-ene-1-carboxylic acid using (R)-2-amino-2-phenylethan-1-ol, which gives the enantiomer opposite to that provided in Example 2. The (-) symbol is assigned to %ee to distinguish between the two enantiomers and does not represent the optical rotation.

[0179] (Z)-6-Hydroxy-1-methylcycloocta-4-ene-1-carboxylic acid (8.00 g, 1 eq, 43.4 mmol) was dissolved in 900 isopropyl acetate at 68 °C in a 2 L three-necked flask (a trace amount of white insoluble material adhered to the glass and remained there throughout the first step). (R)-2-Amino-2-phenylethan-1-ol (5.96 g, 1 eq, 43.4 mmol) was added and the mixture was stirred at 135 rpm using an overhead stirrer.

[0180] The clear mixture was cooled at 10 °C / h and seeded every time it was cooled twice using -61%ee seed crystals. Crystallization occurred at 48 °C. The mixture was further cooled to 35 °C at 10 °C / h and then allowed to reach room temperature overnight.

[0181] Filtration gave 7.2 grams of solid with ee = -55% and 6.6 grams of material in the mother liquor with ee = 83%.

[0182] The 6.2 grams of solid obtained in Step 1 was suspended in 255 mL of isopropyl acetate in a 1 L three-necked flask and heated to 70 °C while stirring at 135 rpm using an overhead stirrer. After 5 minutes, the mixture was allowed to reach room temperature overnight. Filtration gave 5.1 grams of solid with ee = -76% and 1.0 gram of material in the mother liquor with ee = 72%.

[0183] The 3.7 grams of solid obtained in Step 2 was suspended in 20 mL of 2-butanone in a 100 mL round-bottom flask and heated to reflux with stirring using a magnetic stirrer. After adding 12 mL of methanol, the suspension became a clear solution. The mixture was allowed to reach room temperature over night, during which crystallization occurred. By filtration, 2.0 grams of solid with ee = -92% and the substance in the mother liquor of 1.7 grams with ee = -71% were obtained.

[0184] The 1.0 gram of solid obtained in Step 3 was suspended in 10 mL of isopropanol in a 100 mL round-bottom flask and heated to 60 °C with stirring using a magnetic stirrer. After 5 minutes, the mixture was allowed to reach room temperature over night. By filtration, 0.85 grams of solid with ee = -100% and the substance in the mother liquor of 0.15 grams with ee = -56% were obtained.

[0185] Example 6: Synthesis of trans-Cyclooctene (TCO)-Doxorubicin Conjugate 12 Procedure for Compound 11: Process for synthesizing trans-Cyclooctene (TCO)-Doxorubicin Conjugate 11 from TCO starting material 10 in 98% yield on a single gram scale. The reference reports the synthesis of 134 mg of 11 in 68% yield. (Rossin, R. et al. Bioconjugate Chem. 2016, 1697 - 1706).

Chemical formula

[0186] To a solution of doxorubicin HCl (1.0 g, 1.72 mmol, 1.0 equiv) in DMF (10 mL, 10V) was added 10 (874.0 mg, 1.2 equiv), followed by DIPEA (0.9 mL, 3.0 equiv). The mixture was stirred at room temperature for 1.5 h, and HPLC indicated the formation of product 11 (LCAP: 88.5%) and a small amount of doxorubicin (LCAP: 0.3%). The assay yield of 11 was 102.6%. The reaction mixture was diluted with DCM (40 mL) and washed with water (total: 250 mL, monitored by HPLC to confirm that most of the DMF was washed away) and brine (10 mL). The DCM extract was dried over Na2SO4 and concentrated to give a crude residue. 1.7 g of crude product 11 was isolated (95.1% LCAP).

[0187] The residue was purified by silica gel chromatography to give 11 as a red solid. 1.44 g of purified 11 (94.8% LCAP and 97.1% LCWP) was isolated in 98.0% uncorrected yield. Neither 10 nor doxorubicin was detected in the isolated material.

[0188] Since the purity of 11 did not appear to be significantly improved after silica gel purification, this step may not be necessary.

[0189] Procedure for compound 12:

Chemical formula

[0190] The reaction mixture was filtered through a pad of celite and washed with DCM (3 mL). The filtrate was concentrated to give a residue (4.9 g), which was mixed with water (26 mL) and 4 mL of 1N NaOH was added to assist in dissolving the solid at 0 °C. The mixture was then extracted with MTBE, but an emulsion was formed. More water (5 mL), 1N NaOH (2 mL), and MTBE were added, and finally two layers were formed. The aqueous layer (total volume: about 120 mL) was extracted with MTBE (3 × 60 mL) and acidified to pH = 1 - 2 with 1N HCl.

[0191] The orange precipitate was collected by filtration, washed with water, and dried under vacuum to give 1.25 g of 12 (89.3% LCAP) in an 89.2% uncorrected yield.

[0192] Using chromatography, compound 10 (218.5 mg, 1.2 equiv) was added to a solution of doxorubicin HCl (250 mg, 0.431 mmol, 1.0 equiv) in DMF (2.5 mL, 10V), followed by the addition of DIPEA (0.23 mL, 3.0 equiv). The mixture was stirred at room temperature for 3 h, and HPLC indicated the formation of product 11 (LCAP: 91.8%) and a small amount of doxorubicin (LCAP: 0.3%). The assay yield was 92%. To the reaction mixture was added a pre-formed suspension of glycine (323.6 mg, 10 equiv), BSA (0.528 mL, 5 equiv) and DIPEA (1.5 mL, 20 equiv) in 5 mL of DCM, and the mixture was stirred at room temperature for 2 - 3 h. The resulting mixture was stirred at room temperature for 25 h. After filtration and concentration, the residue was subjected to reverse-phase ISCO. The collected fractions were lyophilized.

[0193] 10 - 12 One-pot method (alternative method) Reverse addition order: Compound 10 (218.5 mg, 1.2 equiv) was added to a solution of doxorubicin HCl (250 mg, 0.431 mmol, 1.0 equiv) in DMF (2.5 mL, 10V), followed by the addition of DIPEA (0.23 mL, 3.0 equiv). The mixture was stirred at room temperature for 1 h, and HPLC indicated the formation of product 11 (LCAP: 88.8%) and a small amount of doxorubicin (LCAP: 0.5%). The assay yield was 93.3%. This reaction mixture was used directly as described below. i) A suspension of glycine (64.7 mg, 0.86 mmol, 10 equiv) in 1 mL of DCM was added with BSA (0.105 mL, 5 equiv) and DIPEA (0.30 mL, 20 equiv) under nitrogen at room temperature. The mixture was refluxed for 2 h and then cooled to room temperature. To this was added the reaction mixture of 11 (0.5 mL). The resulting mixture was heated at 40 °C for 5 h and monitored by HPLC. The reaction mixture was then cooled to room temperature, filtered through a pad of celite, and washed with DCM. The filtrate was concentrated to give a residue (0.64 g), which was mixed with 0.2 N NaOH (0.5 mL), and the mixture was extracted with MTBE (2 × 1 mL). The aqueous layer was then acidified to pH = 4 - 5 with 1 N HCl (0.2 mL). A gummy precipitate formed and was collected, showing 88.7% LCAP at 12. The aqueous solution was mainly a mixture of water and DMF. ii) A suspension of glycine (64.7 mg, 0.862 mmol, 10 equiv) in 1 mL of DCM was added with BSA (0.105 mL, 10 equiv) and DIPEA (0.30 mL, 40 equiv) under nitrogen at room temperature. The mixture was stirred at room temperature for 5 min, and then the reaction mixture [24-R174] (0.5 mL) was added. The resulting mixture was stirred at room temperature for 22 h. HPLC showed 90.4% LCAP at 12, and there were no other peaks with >5% LCAP. The reaction mixture was filtered through a pad of celite and washed with DCM. The filtrate was concentrated to give a residue, which was subjected to reverse-phase ISCO purification. The collected fractions were lyophilized.

[0194] Comparative synthesis: Conversion from 11 to 12 using TMSCl as a protecting reagent: 6 mL of 60% A suspension of glycine (89.3 mg, 1.19 mmol, 10 equiv) in CHCl3 / MeCN was added with TMSCl (127.7 mg, 10 equiv) at room temperature under nitrogen. The mixture was refluxed for 2 h and then cooled to room temperature. DIPEA (0.41 mL, 20 equiv) was added, followed by compound 11 (100.0 mg, 1.0 equiv). The resulting mixture was heated at 65 °C for 4.5 h and monitored by HPLC. Then, the reaction was diluted with water (10 mL) and extracted with DCM (3 × 25 mL). The DCM extract was purified by silica gel chromatography to obtain compound 12 (7.3 mg, 24-165-2, LCAP of 12: 78.8%). The aqueous layer was purified by reverse-phase ISCO (0-50% MeCN / water) to obtain 12 (19.6 mg, LCAP of 12: 87.6%). The isolated (uncorrected) yield was 28.3%.

[0195] Formation of Compound-12-Na: The 2000 mL flask was equipped with an overhead stirrer, a temperature probe, and a nitrogen inlet / outlet. Acetone (5 volumes, 128 mL) was placed in the flask and stirred at 20-25 °C under nitrogen. Crude compound 12 (25.6 g, 0.0315 mol, 1 equiv, amount from weight assay %) was slurried in some acetone (7 volumes, 179 mL) and placed in the flask. The remaining acetone was used to rinse the free acid of compound 12 in the flask and placed in the 2000 mL flask. The mixture was purged with nitrogen for a short time and then blanketed under nitrogen.

[0196] Water (3.3 volumes, 84.5 mL, degassed under vacuum to remove oxygen) was added dropwise to the stirred suspension at 20-25 °C. The mixture was completely dissolved (confirmed with a flashlight).

[0197] NaHCO3 (0.592 M, 5% in USP water, 53.3 mL, approximately 1 equiv, degassed under vacuum) was added dropwise to the mixture with stirring at 20-25 °C under nitrogen. The mixture was filterable and stirred at 20-25 °C for about 30 min.

[0198] To the solution obtained in a 2000 mL flask, acetone (about 35 volumes, 896 mL) was added little by little at 19 - 24 °C over about 10 minutes to form a solid suspension. The mixture was stirred at 20 - 24 °C for about 30 minutes.

[0199] Stirring was stopped and the solids were allowed to precipitate to the bottom of the flask (for more than about 1 minute). The mixture was filtered. The flask was rinsed with acetone (3 × 75 mL) and the rinse was used to wash the solid cake.

[0200] The wet solid was transferred to a 500 mL round - bottom flask and vacuum - dried at room temperature (20 - 25 °C) until a constant weight was obtained.

[0201] Example 7: Synthesis of trans - cyclooctene (TCO) - doxorubicin conjugate 12 - Ala

Chemical formula

[0202] Example 8: Comparative Example Evaluation of an alternative synthetic approach to trans-cyclooctene (TCO)-doxorubicin conjugate (Dox-TCO-Gly).

[0203] Direct coupling of glycine to Dox-TCO-NHS (without protecting group) is inefficient.

Chemical Structure

Chemical Structure

[0204] Alternative activating group: PNP gives lower Dox coupling yields compared to NHS PNP - 53%

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Chem.

[0205] Direct alcohol mono - activation of TCO - carboxylic acid activation is preferred

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Chem.

[0206] Example 9: Pecidartinib-TCO-glycine conjugate by the BSA protection method: This example provides a method for attaching a TCO starting material, such as those described herein (e.g., Compound 10), to pecidartinib. Further modification of Compound 15 with an amino acid moiety (e.g., glycine) is contemplated.

Chem.

[0207] To a solution of Compound 13 (418 mg, 1.0 mmol) in DMF (10 mL) at 0 °C was added NaH (approx. 60%, 44 mg, 1.1 mmol). The reaction mixture was stirred under N2 for 1 hour, then bis-NHS-TCO (398 mg, 1.0 mmol) was added. The resulting mixture was stirred at room temperature for 18 hours. The reaction was quenched with water (10 mL). The product was extracted with ethyl acetate (2 × 40 mL). The combined organic layers were washed with water (4 × 15 mL) and brine (15 mL), dried (MgSO4), and evaporated in vacuo. The product was purified by flash chromatography on silica gel eluting with EA / Hex (0% - 100%) to give Intermediate 14 (463 mg, 64%) as a white solid. LCMS: R t = 1.281, m / z 725 [M+1] +

Chem.

[0208] To a solution of N-hydroxysuccinimide ester 14 (200 mg, 0.28 mmol) and DMF (1.6 mL) was added a solution of glycine (207 mg, 2.8 mmol), N,O-bis(trimethylsilyl)acetamide (285 mg, 1.4 mmol) and DIPEA (724 mg, 5.6 mmol) in DCM (3.2 mL). The resulting mixture was stirred at room temperature for 16 h. Monitoring the reaction by LCMS and HPLC showed that most (68%) of the contents was the desired product compound 15 (m / z 684.8(+) and 682.5(-), MW: 685.1). The reaction mixture was diluted with DCM (10 mL) and then filtered through a pad of celite. The filtrate was concentrated to dryness. The residue was purified by preparative HPLC (0.1% formic acid as buffer) to give compound 15 (116.2 mg, 61%) as a white solid. LCMS:R t = 1.013, m / z 685 [M+1] + and 1368 [2M+1] + 。 1 H NMR (300 MHz, CHCl3) δ 8.61 (s, 1H), 8.46 (d, J = 1.8 Hz, 1H), 7.94 - 7.80 (m, 2H), 7.68 - 7.60 (m, 2H), 7.57 (s, 1H), 7.50 (dd, J = 8.7 and 1.8 Hz, 1H), 6.50 (d, J = 9.0 Hz, 1H), 6.34 - 6.16 (m, 2H), 5.66 (dd, J = 16.2 and 2.4 Hz, 1H), 5.57 (s, 1H), 4.59 (s, 2H), 3.92 - 3.80 (m, 4H), 2.38 - 1.80 (m, 7H), 1.74 - 1.68 (m, 1H), 1.17 (s, 3H).

[0209] Example 10: Etoposide-TCO conjugate This example provides a method for attaching a TCO starting material, such as those described herein (e.g., compound 10), to etoposide.

Chemical formula

[0210] To a solution of etoposide (50 mg, 0.08 mmol) in 5 mL of DMF, TCO-PNP (30 mg, 0.10 mmol) and DMAP (21 mg, 0.16 mmol) were added. The mixture was stirred for 3 days and quenched with 20 mL of water. The mixture was extracted with EtOAc (3 × 30 mL), and the combined organic phases were dried and concentrated. The residue was purified by column to give etoposide-TCO compound 16 (30 mg, 54%). 1 H NMR (500 MHz, CDCl3) δ 6.84 (s, 1H), 6.53 (s, 1H), 6.27 (s, 2H), 6.03 - 5.85 (m, 3H), 5.51 (dd, J = 16.5, 1.7 Hz, 1H), 5.33 (s, 1H), 4.92 (d, J = 3.4 Hz, 1H), 4.74 (q, J = 5.0 Hz, 1H), 4.60 (dd, J = 15.7, 6.4 Hz, 2H), 4.42 (dd, J = 26.1, 16.7 Hz, 1H), 4.29 - 4.12 (m, 2H), 3.68 (s, 6H), 3.62 (dd, J = 17.9, 9.1 Hz, 1H), 3.59 - 3.52 (m, 1H), 3.41 - 3.36 (m, 1H), 3.37 - 3.22 (m, 5H), 2.86 (tdd, J = 10.9, 8.0, 3.3 Hz, 1H), 2.49 (d, J = 10.3 Hz, 1H), 2.19 (t, J = 11.9 Hz, 1H), 2.08 - 1.94 (m, 2H), 1.89 (dt, J = 15.1, 6.4 Hz, 1H), 1.68 (ddd, J = 19.0, 15.3, 9.7 Hz, 2H), 1.59 - 1.46 (m, 1H), 1.38 (d, J = 5.0 Hz, 3H), 1.22 - 1.10 (m, 1H), 0.81 (td, J = 14.6, 5.6 Hz, 1H).

[0211] Example 11: Aniline mustard-TCO conjugate [Chemical formula] To a solution of 8-1 (212 mg, 0.72 mmol) in DMF (3 mL) was added 8-2 (305 mg, 0.72 mmol) and DIEA (279 mg, 2.17 mmol). The solution was stirred at room temperature overnight. After removing the solvent, DCM (30 mL) was added. The organic matter was washed with saturated NaHCO3 (40 mL), water (30 mL), and brine (20 mL), dried over Na2SO4, and concentrated to obtain a residue. The residue was triturated with ether (2 × 5 mL) and dried to give compound 8-3 (310 mg, 86%) as a pale yellow solid.

[0212] To a solution of 8-3 (310 mg, 0.62 mmol) in THF (4 mL) and H2O (1 mL) was added LiOH.H2O (77 mg, 1.86 mmol) and DIEA (279 mg, 2.17 mmol). The solution was stirred at room temperature overnight. After removing the solvent, the residue was purified by preparative HPLC (water and ACN, 0.1% formic acid) to give compound 8-4 (140 mg, 56%).

[0213] To a solution of 8-4 (140 mg, 0.34 mmol) in DCM (4 mL) was added TEA (172 mg, 1.72 mmol) and MsCl (79 mg, 0.85 mmol). The solution was stirred at room temperature for 4 hours. DCM (10 mL) was added. The organic matter was washed with water (2 × 10 mL) and brine (10 mL), dried over Na2SO4, and concentrated. The residue was dried under high vacuum to obtain the crude product 8-5 (171 mg).

[0214] To a solution of 8-5 (170 mg, 0.3 mmol) in DMF (2 mL) was added LiCl (252 mg, 6.0 mmol). The mixture was stirred at room temperature for 2 hours and then at 60 °C overnight. After removing the solvent, DCM (10 mL) was added. The organic layer was washed with water (10 mL) and brine (10 mL), dried over Na2SO4, and concentrated to obtain a residue. The residue was purified by preparative HPLC (water and ACN, 0.1% formic acid) to give compound 8-6 (86 mg, 64% over 2 steps) as an off-white powder. LCMS: 443 [M+H] + 。 11H NMR (300 MHz, CD3OD) δ 7.25 (d, J = 7.8 Hz, 2H), 6.72 (d, J = 7.8 Hz, 2H), 6.00 (m, 1H), 5.71 (m, 1H), 5.18 (s, 1H), 3.71 - 3.61 (m, 8H), 2.27 - 1.67 (m, 8H), 1.28 (s, 1H), 1.12 (s, 3H). * * *

[0215] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0216] The disclosure illustrated herein can be suitably practiced without any element(s) and / or limitation(s) not specifically disclosed herein. Thus, for example, terms such as "comprising," "including," "containing," etc. should be read in a broad and non - limiting sense. Further, the terms and expressions used herein are used as terms of description and not of limitation, and are not intended to exclude any equivalents or portions of the features shown and described, but it should be recognized that various modifications are possible within the scope of the claimed disclosure.

[0217] Accordingly, although the disclosure has been specifically disclosed by way of preferred embodiments and optional features, it should be understood that modifications, improvements, and variations of the disclosure embodied herein can be made by those skilled in the art, and such modifications, improvements, and variations are considered to be within the scope of the disclosure. The materials, methods, and examples provided herein are representative of preferred embodiments and are illustrative and are not intended to limit the scope of the disclosure.

[0218] The present disclosure has been described herein in a broad and comprehensive sense. Each of the more narrow species and subgeneric groupings that fall within the comprehensive disclosure also forms part of the invention. This includes a comprehensive description of the invention with provisos or negative limitations that exclude any subject matter from the generic concept, whether or not the deleted matter is specifically recited herein.

[0219] In addition, when features or aspects of the present disclosure are described from the perspective of a Markush group, those skilled in the art will recognize that the present disclosure is also described from the perspective of any individual member or subgroup of members of the Markush group.

[0220] All publications, patent applications, patents, and other references mentioned herein are hereby expressly incorporated by reference in their entirety to the same extent as if each were individually incorporated by reference. In case of conflict, the present specification, including definitions, will control.

[0221] The present disclosure has been described in connection with the above embodiments, but it should be understood that the foregoing description and examples are intended to illustrate and not to limit the scope of the present disclosure. Other aspects, advantages, and modifications within the scope of the present disclosure will be apparent to those skilled in the art to which the present disclosure pertains. The present invention provides, for example, the following items. (Item 1) A compound of formula I [Chemical formula] (wherein, R 1 is selected from the group consisting of -OR 4 , optionally substituted heterocyclyl, and amino acid moieties, n is 0, 1, 2, 3, or 4, each R 2 is independently C 1-4 alkyl, C 1-4 haloalkyl, and C 1-4 alkoxy, D is the payload part, R 4 which is hydrogen or C 1-4 alkyl), or a salt thereof, and a process for preparing the same, comprising reacting a compound of formula II with

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Table 1-3

Table 1-4

Claims

[Claim 1] The invention described in the present specification.

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