Peroxidoredoxin 3 inhibitors and methods for treating cancer

Abstract

Provided according to some embodiments are compounds of Formula I, 2-aryl, 2-heteroaryl, 2-cycloalkyl or 2-heterocycle substituted thiazole-4-carboxamide) acrylamide) acrylate compounds, as peroxide redoxin 3 (PRX3) inhibitors, or a pharmaceutically acceptable salt or prodrug thereof. Also provided are pharmaceutical compositions comprising the compounds of Formula I, or a pharmaceutically acceptable salt or prodrug thereof, and methods for treating cancer and inhibiting PRX3. # imgabs0 #

Description

[0001] Statement of Government Support

[0002] This invention was made with government support under contract No. R01GM072866 awarded by the National Institutes of Health. The United States government has certain rights in this invention. Background Art

[0003] A central hallmark of cellular tumorigenesis is metabolic alterations, which lead to increased levels of reactive oxygen species (ROS) and mitochondrial ROS (mROS). Cairns et al. (2011) Nat Rev Cancer 11, 85 - 95; Weinberg et al. (2009) Cell Mol Life Sci 66, 3663 - 3673; Weinberg et al. (2009) Ann N Y Acad Sci 1177, 66 - 73; Weinberg et al. (2010) Proc Natl Acad Sci USA 107, 8788 - 8793. In response to this oncogenic transformation, cells reorganize their antioxidant capacity to survive, proliferate, and metastasize. Specifically, the increased ROS levels induced by oncogenes activate the oncogenic transcription factor FOXM1, inducing the expression of FOXM1 target genes, including the mitochondrial antioxidant enzymes superoxide dismutase 2 and peroxiredoxin 3 (PRX3). Park et al. (2009) EMBO J 28, 2908 - 2918; Nonn et al. (2003) Mol Cancer Res 1, 682 - 689.

[0004] PRX3 is a peroxidase responsible for metabolizing approximately 90% of mitochondrial hydrogen peroxide (H2O2) (Cox et al. (2009) Biochem J 425, 313 - 325), and this specific ROS regulation is known to involve several important processes in tumor progression, including proliferation, apoptosis, migration, and metastasis. The GEPIA2 database of paired patient samples (tumor versus normal) illustrates how PRX3 transcript levels are elevated in 15 / 32 (46.9%) of the collected tumor tissues, including many cancer forms with significant unmet medical needs. Tang et al. (2019) Nucleic Acids Res 47, W556 - W560. PRX3 protein expression and mROS levels are correlated with sensitivity to natural products and the PRX3 inhibitor thiostrepton (TS) in patient - derived malignant mesothelioma cell lines. Nelson et al. (2021) Antioxidants (Basel) 10, 150.

[0005] PRX3 expression supports the growth of malignant mesothelioma (MM) and ovarian tumor (OvCa) cells. Cunniff et al. (2015) PloS one 10, e0127310; Myers (2016) Free Radic Biol Med 91, 81-92; Yoshikawa et al. (2016) Oncol Rep 35, 2543-2552; Wang et al. (2013) Tumour Biol 34, 2275-2281. PRX3 expression levels in OvCa and cervical cancer are also associated with poor patient outcomes. Li et al. (2018) Biosci Rep 38. The following additional features further support PRX3 as a promising molecular target for cancer therapy: (i) There are no cancer mutations in the PRX3 gene known to support the development of drug resistance; (ii) PRX3 KO mice survive and reach maturity; only an increase in basal oxidative stress levels is observed in various challenge models (Li et al. (2007) Biochem Biophys Res Commun 355, 715-721; Lee (2020) Antioxidants (Basel) 9); and (iii) Partial knockdown of PRX3 via shRNA slows tumor cell proliferation and significantly reduces FOXM1 expression at the RNA and protein levels (Cunniff et al. (2015) PloS one 10, e0127310).

[0006] The study by Corsello et al. (Nature Cancer 2020 1(2):235-248) tested the ability of 4,518 drugs from the Drug Repurposing Hub of the Broad Institute to kill 578 cancer cell lines. Thiostrepton (TS), an insoluble thiopeptide antibiotic, showed meaningful efficacy in 403 tumor cell lines derived from a variety of tissues. Our team has demonstrated that TS acts by irreversibly crosslinking two essential catalytic cysteine residues in PRX3, inactivating peroxidase activity and increasing ROS to levels incompatible with survival. Nelson et al. (2021) Antioxidants (Basel) 10, 150; Cunniff et al. (2015) PloS one 10, e0127310; Newick et al. (2012) PloS one 7, e39404. Since this irreversible crosslinking occurs across the homodimer interface, the inactivated PRX3 is significantly larger in mass, and we can track PRX3 crosslinking in our cell and animal models.

[0007] Several mechanisms have been proposed for the cytotoxicity of TS against cancer cells: (i) interaction with the oncogenic transcription factor FOXM1 (Hegde et al. (2011) Nat Chem 3, 725 - 731), (ii) inhibition of the 20 / 26S proteasome (Bhat et al. (2009) PloS one 4, e6593; Bird et al. (2020) ACS Chem Biol 15, 2164 - 2174), (iii) binding to the large subunit of the ribosome (Zhang et al. (2005) Antibiotic susceptibility of mammalian mitochondrial translation. FEBS Lett 579, 6423 - 6427; Harms et al. (2008) Mol Cell 30, 26 - 38), and (iv) covalent adduction and crosslinking of PRX3 by our team (Nelson et al. (2021) Antioxidants (Basel) 10, 150; Cunniff et al. (2015) PloS one 10, e0127310). We show that in a cellular model of MM, TS sensitivity is greatly reduced upon knockdown of PRX3, indicating that PRX3 inhibition is key to driving TS cytotoxicity. Inhibiting PRX3 also significantly increases mitochondrial ROS that drive TS-mediated cell death. The increased ROS regulates FOXM1 expression, while the increased production of mitochondrial ROS is also shown to disassemble the 26S proteasome complex (Livnat-Levanon et al. (2014) Cell Rep 7, 1371 - 1380; Segref et al. (2014) Cell Metab 19, 642 - 652), further complicating the interpretation of the mode of action of TS.

[0008] Despite the effectiveness of TS in cellular and animal models of cancer, this natural product has severe limitations in its utility as a chemotherapeutic. First, it is very large, very poorly soluble and does not exhibit any preferred drug-like properties. Second, currently this molecule is produced sequentially by bacterial fermentation followed by organic extraction and purification. Although synthetic routes for synthesis have been published, it involves multiple steps, is expensive and has low yields. Ayida et al. (2005) Bioorg Med Chem Lett 15, 2457 - 2460.

[0009] Improved PRX3 inhibitors that can address some of these issues are needed. Summary of the Invention

[0011] According to some embodiments, provided herein are compounds of formula I or pharmaceutically acceptable salts or prodrugs thereof:

[0012]

[0013] wherein R 1 is aryl, heteroaryl, cycloalkyl or heterocycle, and the aryl, heteroaryl, cycloalkyl or heterocycle is optionally substituted with one or more groups selected from: alkyl, carboxyl, carbamate, urea, amide, amino, ether, ester and halo. In some embodiments, when R 1 is pyridine or pyrazine, the pyridine or pyrazine is substituted with one or more groups selected from: alkyl, carboxyl, carbamate, urea, amide, amino, ether, ester and halo.

[0014] In some embodiments, the aryl, heteroaryl, cycloalkyl or heterocycle is substituted with one or more groups selected from: alkyl, carboxyl, carbamate, urea, amide and halo. In some embodiments, the aryl, heteroaryl, cycloalkyl or heterocycle is substituted with carbamate or amide. In some embodiments, the aryl, heteroaryl, cycloalkyl or heterocycle is substituted with alkyl carbamate.

[0015] In some embodiments, R 1 is a group having the following structure:

[0016]

[0017] wherein:

[0018] n is 0, 1, 2 or 3;

[0019] m is 0, 1 or 2;

[0020] X is absent or is O, NR 3 or CH2;

[0021] Y is absent or is O, NR 3 or CH2;

[0022] Z 1 and Z 2 are each independently O, N or C;

[0023] R 2 is alkyl (e.g., having 1-8 carbon atoms, straight-chain or branched-chain), wherein the alkyl is optionally substituted (e.g., substituted with halo, amino, ether, alkoxy or carbamate), or heterocycle; and

[0024] R 3 is H or alkyl (e.g., having 1-8 carbon atoms, straight-chain or branched-chain),

[0025] wherein * represents the connection of the group in the compound of formula I.

[0026] In some embodiments, Z 1 and Z 2 are each independently N or C.

[0027] In some embodiments, R 1 is a group having the following structure:

[0028]

[0029] wherein:

[0030] n is 0, 1, 2, or 3;

[0031] m is 0, 1, or 2;

[0032] X is O or CH2; and

[0033] R 2 is alkyl (e.g., having 1-8 carbon atoms, straight-chain or branched-chain), wherein the alkyl is optionally substituted (e.g., substituted by halo, amino, ether, alkoxy, or carbamate), or a heterocycle,

[0034] where * represents the attachment of the group in the compound of formula I.

[0035] In some embodiments, R 1 is a group having the following structure:

[0036]

[0037] wherein:

[0038] n is 0, 1, 2, or 3;

[0039] X is O or CH2; and

[0040] R 2 is alkyl (e.g., having 1-8 carbon atoms, straight-chain or branched-chain), wherein the alkyl is optionally substituted (e.g., substituted by halo, amino, ether, alkoxy, or carbamate), or a heterocycle,

[0041] where * represents the attachment of the group in the compound of formula I,

[0042] In some embodiments, R 1 is a group having the following structure:

[0043]

[0044] wherein:

[0045] n is 0, 1, 2, or 3;

[0046] X is O or CH2;

[0047] R 2 is an alkyl group (e.g., having 1 - 8 carbon atoms, straight - chain or branched - chain), wherein said alkyl group is optionally substituted (e.g., substituted by halogen, amino, ether, alkoxy or carbamate), or a heterocycle; and

[0048] R 3 is H or an alkyl group (e.g., having 1 - 8 carbon atoms, straight - chain or branched - chain),

[0049] wherein * represents the connection of the groups in the compound of formula I.

[0050] Also provided are pharmaceutical compositions comprising a compound as taught herein or a pharmaceutically acceptable salt or prodrug thereof. In some embodiments, the composition is formulated for oral or parenteral (e.g., intravenous, intrapleural, intraperitoneal or intraovarian) administration. In some embodiments, the composition is formulated for oral administration and is in the form of a capsule, cachet, lozenge or tablet. In some embodiments, the formulation is provided in unit dosage forms of 1 mg to 10 grams of the compound, pharmaceutically acceptable salt or prodrug.

[0051] Further provided is a method of treating cancer in a subject in need thereof, which comprises administering to the subject a therapeutically effective amount of a compound of formula I or a pharmaceutically acceptable salt or prodrug thereof. Also provided is a compound of formula I or a pharmaceutically acceptable salt or prodrug thereof for treating cancer in a subject in need thereof or for preparing a medicament for treating cancer.

[0052] In some embodiments, the cancer has PRX3 expression.

[0053] In some embodiments, the subject is a human subject. In some embodiments, the subject is a non - human animal subject (e.g., a non - human mammalian subject).

[0054] In some embodiments, the administration is effected by administering a pharmaceutical composition comprising the compound or a pharmaceutically acceptable salt or prodrug thereof.

[0055] In some embodiments, the administration further comprises administering bortezomib, carboplatin, paclitaxel, an immunotherapeutic agent or a combination thereof. In some embodiments, the administration further comprises administering doxorubicin.

[0056] Further provided is a method of inhibiting PRX3 in a subject in need thereof, which comprises administering to the subject a therapeutically effective amount of a compound of formula I or a pharmaceutically acceptable salt or prodrug thereof. Summary of the Invention

[0057] The present invention is explained in more detail below. This description is not intended to be an exhaustive catalog of all the different ways in which the present invention can be implemented or all the features that can be incorporated into the present invention. For example, features described with respect to one embodiment can be incorporated into other embodiments, and features described with respect to a particular embodiment can be deleted from that embodiment. In addition, in view of the present disclosure, numerous variations and additions to the various embodiments proposed herein will be apparent to those skilled in the art, and such variations and additions do not depart from the present invention. Accordingly, the following specification is intended to illustrate some specific embodiments of the present invention and is not intended to exhaustively specify all of its permutations, combinations, and variations.

[0058] The disclosures of all patent references cited herein are incorporated herein by reference to the extent that they are consistent with the disclosure set forth herein. Unless the context clearly indicates otherwise, as used herein in the specification and claims of the present invention, the singular forms "a", "an", and "the" are also intended to include the plural forms.

[0059] I. Definitions

[0060] As used herein in the accompanying chemical structures, "H" refers to a hydrogen atom. "C" refers to a carbon atom. "N" refers to a nitrogen atom. "S" refers to a sulfur atom. "O" refers to an oxygen atom.

[0061] Unless otherwise specified, the nomenclature used herein to describe chemical groups or moieties follows the convention where the name is read from left to right and the point of attachment to the rest of the molecule is on the right hand side of the name. For example, the group "alkylamino" is attached to the rest of the molecule at the amino terminus, whereas the group "aminoalkyl" is attached to the rest of the molecule at the alkyl terminus.

[0062] As used herein, "alkyl" refers to a saturated straight-chain or branched-chain hydrocarbon containing 1-10 carbon atoms. Representative examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, 3-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, n-heptyl, n-octyl, n-nonyl, n-decyl, and the like. As used herein, "lower alkyl" is a subset of alkyl and refers to a straight-chain or branched-chain hydrocarbon group containing 1-4 carbon atoms. Representative examples of lower alkyl include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and the like. The alkyl can be optionally substituted with one or more suitable substituents such as halo, hydroxy, carboxy, amine, and the like.

[0063] As used herein, "cycloalkyl" refers to a saturated cyclic hydrocarbon containing 1 to 10 carbon atoms. Representative examples of cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and the like. The cycloalkyl may optionally be substituted with one or more suitable substituents such as halo, hydroxy, carboxy, amine, and the like.

[0064] As used herein, "aryl" refers to a monocyclic carbocyclic ring system or a fused or directly adjacent bicyclic carbocyclic ring system having one or more aromatic rings. Examples include, but are not limited to, phenyl, indanyl, indenyl, tetrahydronaphthyl, biphenyl, naphthyl, azulyl, and the like. The aryl may optionally be substituted with one or more suitable substituents such as alkyl, halo, hydroxy, carboxy, amine, and the like.

[0065] As used herein, "heteroaryl" refers to a monovalent aromatic group having a single ring or two fused or directly adjacent rings and containing at least one (typically 1 to 3) heteroatoms independently selected from nitrogen, oxygen, and sulfur in at least one ring. Examples include, but are not limited to, pyrrole, imidazole, thiazole, oxazole, furan, thiophene, triazole, pyrazole, isoxazole, isothiazole, pyridine, pyrazine, pyridazine, pyrimidine, triazine, benzothiophene, benzofuran, indole, benzimidazole, benzothiazole, quinoline, isoquinoline, quinazoline, quinoxaline, phenyl-pyrrole, phenyl-thiophene, and the like. The heteroaryl may optionally be substituted with one or more suitable substituents such as alkyl, halo, hydroxy, carboxy, amine, and the like.

[0066] As used herein, "heterocycle" refers to a saturated or partially unsaturated cyclic hydrocarbon having at least one (typically 1 to 3) heteroatoms independently selected from nitrogen, oxygen, and sulfur. The heterocycle may be a monocyclic heterocycle, a bicyclic heterocycle, or a tricyclic heterocycle. The heterocycle may optionally be substituted with one or more suitable substituents such as alkyl, halo, hydroxy, carboxy, amine, and the like.

[0067] "Monocyclic heterocycle" means a 3-membered, 4-membered, 5-membered, 6-membered, 7-membered, or 8-membered ring containing at least one heteroatom and not being aromatic. Representative examples of monocyclic heterocycles include, but are not limited to, azetidinyl, azepanyl, aziridinyl, diazepanyl, 1,3-dioxanyl, 1,3-dioxolanyl, dihydropyranyl (including 3,4-dihydro-2H-pyran-6-yl), 1,3-dithiolanyl, 1,3-dithianyl, imidazolidinyl, isothiazolidinyl, isoxazolidinyl, morpholinyl, oxadiazolanyl, oxazolidinyl, piperazinyl, piperidinyl, pyranyl, pyrazolidinyl, pyrrolidinyl, tetrahydrofuranyl, tetrahydropyranyl (including tetrahydro-2H-pyran-4-yl), tetrahydrothiophenyl, thiadiazolanyl, thiazolidinyl, thiomorpholinyl, 1,1-dioxidothiomorpholinyl (sulfuryl thiomorpholine), thiopyranyl, and trithianyl.

[0068] "Bicyclic heterocycle" means a monocyclic heterocycle fused to an aryl group, a monocyclic heterocycle fused to a monocyclic cycloalkyl or cycloalkenyl group, or a monocyclic heterocycle fused to another monocyclic heterocycle. Representative examples of bicyclic heterocycles include, but are not limited to, 3,4-dihydro-2H-pyranyl, 1,3-benzodioxolyl, 1,3-benzodithiolyl, 2,3-dihydro-1,4-benzodioxinyl, 2,3-dihydro-1-benzofuranyl, 2,3-dihydro-1-benzothienyl, 2,3-dihydro-1H-indolyl, 3,4-dihydroquinolin-2(1H)-one, and 1,2,3,4-tetrahydroquinolinyl.

[0069] "Tricyclic heterocycle" means a bicyclic heterocycle fused to an aryl group, a bicyclic heterocycle fused to a monocyclic cycloalkyl or monocyclic cycloalkenyl group, or a bicyclic heterocycle fused to a monocyclic heterocycle. Representative examples of tricyclic heterocycles include, but are not limited to, 2,3,4,4a,9,9a-hexahydro-1H-carbazolyl, 5a,6,7,8,9,9a-hexahydrodibenz[b,d]furanyl, and 5a,6,7,8,9,9a-hexahydrodibenz[b,d]thienyl.

[0070] The terms "halo" and "halogen" refer to fluorine (-F), chlorine (-Cl), bromine (-Br), or iodine (-I).

[0071] "Haloalkyl" refers to one or more halo groups attached to the parent molecular moiety through an alkyl group. Examples include, but are not limited to, chloromethyl, fluoromethyl, trifluoromethyl, etc.

[0072] "Carboxy" refers to the group –COOH.

[0073] "Alkoxy" refers to an alkyl or cycloalkyl group as defined herein attached to the main carbon chain through an oxygen atom. Representative examples of "alkoxy" include, but are not limited to, methoxy, ethoxy, propoxy, 2-propoxy, butoxy, tert-butoxy, and hexyloxy.

[0074] "Hydroxy" or "hydroxyl" refers to the group –OH.

[0075] "Amine" or "amino" refers to the group –NH2, where none, one, or two hydrogens can be replaced by an alkyl, cycloalkyl, or aryl group as defined herein.

[0076] "Amide" or "amide group" refers to a group having a carbonyl bonded to a nitrogen atom (e.g., –C(O)NH2), where none, one, or two hydrogens can be replaced by an alkyl, cycloalkyl, heterocycle, or aryl group as defined herein.

[0077] "Ether" refers to a group in which an ether (R-O-R') is present, where R and R' are each independently an alkyl, cycloalkyl or aryl group as defined herein.

[0078] "Ester" refers to a group in which an ester (R-C(O)-O-R') is present, where R and R' are each independently an alkyl, cycloalkyl or aryl group as defined herein.

[0079] "Carbamate" refers to a group in which a carbamate R-O-C(O)NR'R" is present, where R, R' and R" are each independently an alkyl, cycloalkyl or aryl group as defined herein.

[0080] "Urea" refers to a group in which a urea R-NH-C(O)-NH-R' is present, where R and R' are each independently an alkyl, cycloalkyl or aryl group as defined herein.

[0081] As understood in the art, the term "optionally substituted" means that the specified group is unsubstituted or substituted with one or more suitable substituents. A "substituent" that "substitutes" is a group that replaces one or more hydrogen atoms on the parent organic molecule.

[0082] Pharmaceutically acceptable salts are salts that retain the biological activity required of the parent compound and do not impart undesirable toxicological effects. Examples of such salts are (a) acid addition salts formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, nitric acid, etc.; and salts formed with organic acids such as, for example, acetic acid, oxalic acid, tartaric acid, succinic acid, maleic acid, fumaric acid, gluconic acid, citric acid, malic acid, ascorbic acid, benzoic acid, tannic acid, palmitic acid, alginic acid, polyglutamic acid, naphthalenesulfonic acid, methanesulfonic acid, p-toluenesulfonic acid, naphthalenedisulfonic acid, polygalacturonic acid, and the like; and (b) salts formed from elemental anions such as chlorine, bromine and iodine.

[0083] II. Active Compounds

[0084] Active compounds useful as PRX3 inhibitors according to the present invention are provided below. Unless otherwise stated, the structures described herein are also intended to include all enantiomers, diastereomers and geometric (or conformational) forms of said structures; for example, the R and S configurations for each asymmetric center, the (Z) and (E) double bond isomers, and the (Z) and (E) conformational isomers. Accordingly, single stereochemical isomers as well as enantiomeric, diastereomeric and geometric (or conformational) mixtures of the compounds of the present invention are within the scope of the present invention. Unless otherwise stated, all tautomeric forms of the compounds of the present invention are within the scope of the present invention. Tautomeric forms include the keto-enol tautomers of the compounds. In addition, unless otherwise stated, all rotameric forms of the compounds of the present invention are within the scope of the present invention.

[0085] Unless otherwise stated, the structures described herein also mean compounds that differ only in the presence of one or more isotopically enriched atoms. For example, compounds having the structure of the present invention are within the scope of the present invention except that hydrogen is replaced by deuterium or tritium or carbon is replaced by carbon enriched with 13C or 14C. Such compounds can be used, for example, as analytical tools or probes in biological assays.

[0086] According to some embodiments, provided herein as an active compound is a compound of Formula I or a pharmaceutically acceptable salt or prodrug thereof:

[0087]

[0088] wherein R 1 is aryl, heteroaryl, cycloalkyl or heterocycle, and the aryl, heteroaryl, cycloalkyl or heterocycle is optionally substituted with one or more groups selected from: alkyl, carboxyl, carbamate, urea, amide, amino, ether, ester and halo. In some embodiments, when R 1 is pyridine or pyrazine, the pyridine or pyrazine is substituted with one or more groups selected from: alkyl, carboxyl, carbamate, urea, amide, amino, ether, ester and halo.

[0089] In some embodiments, the aryl, heteroaryl, cycloalkyl or heterocycle is substituted with one or more groups selected from: alkyl, carboxyl, carbamate, urea, amide and halo. In some embodiments, the aryl, heteroaryl, cycloalkyl or heterocycle is substituted with carbamate or amide. In some embodiments, the aryl, heteroaryl, cycloalkyl or heterocycle is substituted with alkyl carbamate.

[0090] In some embodiments, R 1 is a group having the following structure:

[0091]

[0092] wherein:

[0093] n is 0, 1, 2 or 3;

[0094] m is 0, 1 or 2;

[0095] X is absent or is O, NR 3 or CH2;

[0096] Y is absent or is O, NR 3 or CH2;

[0097] Z 1 and Z 2 are each independently O, N or C;

[0098] R 2is an alkyl group (e.g., having 1 - 8 carbon atoms, straight - chain or branched - chain), wherein said alkyl group is optionally substituted (e.g., substituted by halogen, amino, ether, alkoxy or carbamate), or a heterocycle; and

[0099] R 3 is H or an alkyl group (e.g., having 1 - 8 carbon atoms, straight - chain or branched - chain),

[0100] where * represents the attachment of the group in the compound of formula I (i.e., the attachment of the group at position 2 of the thiazole ring).

[0101] In some embodiments, Z 1 and Z 2 are each independently N or C.

[0102] Specific examples of the active compounds include, but are not limited to, those selected from the following:

[0103]

[0104] In some embodiments, R 1 is a group having the following structure:

[0105]

[0106] wherein:

[0107] n is 0, 1, 2 or 3;

[0108] m is 0, 1 or 2;

[0109] X is O or CH2; and

[0110] R 2 is an alkyl group (e.g., having 1 - 8 carbon atoms, straight - chain or branched - chain), wherein said alkyl group is optionally substituted (e.g., substituted by halogen, amino, ether, alkoxy or carbamate), or a heterocycle; and

[0111] where * represents the attachment of the group in the compound of formula I (i.e., the attachment of the group at position 2 of the thiazole ring).

[0112] In some embodiments, R 1 is a group having the following structure:

[0113]

[0114] wherein:

[0115] n is 0, 1, 2 or 3;

[0116] X is O or CH2; and

[0117] R 2is an alkyl group (e.g., having 1-8 carbon atoms, straight-chain or branched-chain), wherein said alkyl group is optionally substituted (e.g., substituted by halogen, amino, ether, alkoxy or carbamate), or a heterocycle; and

[0118] where * represents the attachment of the group in the compound of formula I (i.e., the attachment of the group at position 2 of the thiazole ring).

[0119] Specific examples of the active compounds include, but are not limited to, those selected from the following:

[0120]

[0121]

[0122]

[0123] In some embodiments, R 1 is a group having the following structure:

[0124]

[0125] wherein:

[0126] n is 0, 1, 2 or 3;

[0127] X is O or CH2;

[0128] R 2 is an alkyl group (e.g., having 1-8 carbon atoms, straight-chain or branched-chain), wherein said alkyl group is optionally substituted (e.g., substituted by halogen, amino, ether, alkoxy or carbamate), or a heterocycle; and

[0129] R 3 is H or an alkyl group (e.g., having 1-8 carbon atoms, straight-chain or branched-chain),

[0130] where * represents the attachment of the group in the compound of formula I (i.e., the attachment of the group at position 2 of the thiazole ring).

[0131] Specific examples of the active compounds include, but are not limited to, those selected from the following:

[0132]

[0133]

[0134] Specific examples of the active compounds include, but are not limited to, those selected from the following:

[0135]

[0136]

[0137] Specific examples of the active compound include, but are not limited to, those selected from the following:

[0138]

[0139]

[0140] Specific examples of the active compound include, but are not limited to, those selected from the following:

[0141]

[0142] Specific examples of the active compound include, but are not limited to, those selected from the following:

[0143]

[0144]

[0145]

[0146] In some embodiments, the active compound can form a covalent adduct with PRX3 in a biochemical PRX3 inhibition assay, which can support its PRX3 inhibitory activity.

[0147] In some embodiments, in a cell activity assay (such as the ability to kill cancer cells such as SKOV3 ovarian cancer cells), the active compound can have an EC in the micromolar range 50 , for example, 0.05 micromolar, 0.1 micromolar, 0.25 micromolar or 0.5 micromolar to 10 micromolar, 15 micromolar or 20 micromolar.

[0148] In some embodiments, the active compound can have good solubility, for example, a solubility of at least 0.1 millimolar in an aqueous solution (such as saline, such as phosphate buffered saline, water, etc.), for example, 0.1 - 1 millimolar, or a solubility of at least 1 millimolar in an aqueous solution.

[0149] In some embodiments, the active compound can have good water stability. For example, in some embodiments, the active compound can have no decrease in purity after 24 hours in an aqueous solution.

[0150] In some embodiments, the active compound has no appreciable antimicrobial activity, for example, at a concentration greater than 20 micromolar.

[0151] In some embodiments, the active compound does not inhibit the proteasome and / or does not inhibit FOXM1 DNA binding. These can indicate that the compound has higher specificity for PRX3 than TS.

[0152] III. Methods of Use

[0153] As used herein, "treatment" refers to any type of treatment that confers a benefit on a subject afflicted with a disease or disorder, delays the progression of the disease or disorder or its symptoms, etc. In some embodiments, the treatment is directed to cancer (such as cancer with elevated reactive oxygen species).

[0154] In some embodiments, the subject being treated is a human subject. In some embodiments, the subject is a non-human animal (such as a non-human mammalian subject). Non-human animals can include, but are not limited to, non-human primates, dogs, cats, horses, cows, goats, pigs, sheep, guinea pigs, mice, rats, and rabbits, as well as any other domestic animals, animals of commercial or clinical value, including but not limited to animal models and livestock animals. In some embodiments, the subject is a subject in need of treatment, such as the treatment of the present invention.

[0155] According to some embodiments, cancers that can be treated with an active compound can include, but are not limited to, acoustic neuroma; adenocarcinoma; adrenal cancer; anal cancer; angiosarcoma (e.g., lymphangiosarcoma, lymphangioendotheliosarcoma, angiosarcoma); appendiceal cancer; benign monoclonal gammopathy; bile duct cancer (e.g., cholangiocarcinoma); biliary tract cancer; bladder cancer; bone cancer; breast cancer (e.g., breast adenocarcinoma, breast papillary carcinoma, mammary cancer, breast medullary carcinoma); brain cancer (e.g., meningioma, glioblastoma, glioma (e.g., astrocytoma, oligodendroglioma), medulloblastoma); bronchial cancer; carcinoid tumor; cardiac tumor; cervical cancer (e.g., cervical adenocarcinoma); choriocarcinoma; chordoma; craniopharyngioma; colorectal cancer (e.g., colon cancer, rectal cancer, colorectal adenocarcinoma); connective tissue cancer; epithelial cancer; ductal carcinoma in situ; ependymoma; endothelial sarcoma (e.g., Kaposi's sarcoma, multiple idiopathic hemorrhagic sarcoma); endometrial cancer (e.g., uterine cancer, uterine sarcoma); esophageal cancer (e.g., esophageal adenocarcinoma, Barrett's adenocarcinoma); Ewing's sarcoma; eye cancer (e.g., intraocular melanoma, retinoblastoma); familial eosinophilia; gallbladder cancer; gastric cancer (e.g., gastric adenocarcinoma); gastrointestinal stromal tumor (GIST); germ cell cancer; head and neck cancer (e.g., head and neck squamous cell carcinoma, oral cancer (e.g., oral squamous cell carcinoma), laryngeal cancer (e.g., laryngeal cancer, pharyngeal cancer, nasopharyngeal cancer, oropharyngeal cancer)); hematopoietic system cancers (e.g., leukemia, such as acute lymphoblastic leukemia (ALL) (e.g., B-cell ALL, T-cell ALL), acute myeloid leukemia (AML) (e.g., B-cell AML, T-cell AML), chronic myeloid leukemia (CML) (e.g., B-cell CML, T-cell CML), and chronic lymphocytic leukemia (CLL) (e.g., B-cell CLL, T-cell CLL)); lymphoma, such as Hodgkin lymphoma (HL) (e.g., B-cell HL, T-cell HL) and non-Hodgkin lymphoma (NHL) (e.g., B-cell NHL, such as diffuse large cell lymphoma (DLCL) (e.g., diffuse large B-cell lymphoma), follicular lymphoma, chronic lymphocytic leukemia / small lymphocytic lymphoma (CLL / SLL), mantle cell lymphoma (MCL), marginal zone B-cell lymphoma (e.g., mucosa-associated lymphoid tissue (MALT) lymphoma, nodal marginal zone B-cell lymphoma, splenic marginal zone B-cell lymphoma), primary mediastinal B-cell lymphoma, Burkitt lymphoma, lymphoplasmacytic lymphoma (i.e., Waldenström macroglobulinemia), hairy cell leukemia (HCL), immunoblastic large cell lymphoma, precursor B-lymphoblastic lymphoma, and primary central nervous system (CNS) lymphoma;and T cell NHL, such as precursor T-lymphoblastic lymphoma / leukemia, peripheral T cell lymphoma (PTCL) (such as cutaneous T cell lymphoma (CTCL) (such as mycosis fungoides, Sezary syndrome), angioimmunoblastic T cell lymphoma, extranodal natural killer T cell lymphoma, enteropathy-type T cell lymphoma, subcutaneous panniculitis-like T cell lymphoma, and anaplastic large cell lymphoma); a mixture of one or more leukemias / lymphomas as described above; multiple myeloma; heavy chain disease (such as alpha chain disease, gamma chain disease, mu chain disease); hemangioblastoma; histiocytosis; hypopharyngeal cancer; inflammatory myofibroblastic tumor; immunocyte amyloidosis; kidney cancer (such as nephroblastoma also known as Wilms tumor, renal cell carcinoma); liver cancer (such as hepatocellular carcinoma (HCC), malignant liver cancer); lung cancer (such as bronchogenic carcinoma, small cell lung cancer (SCLC), non-small cell lung cancer (NSCLC), lung adenocarcinoma); leiomyosarcoma (LMS); mastocytosis (such as systemic mastocytosis); melanoma; midline tract carcinoma; multiple endocrine neoplasia syndrome; muscle cancer; myelodysplastic syndrome (MDS); mesothelioma; myeloproliferative disorder (MPD) (such as polycythemia vera (PV), essential thrombocythemia (ET), agnogenic myeloid metaplasia (AMM) also known as myelofibrosis (MF), chronic idiopathic myelofibrosis, chronic myelogenous leukemia (CML), chronic neutrophilic leukemia (CNL), hypereosinophilic syndrome (HES)); nasopharyngeal cancer; neuroblastoma; neurofibroma (such as neurofibromatosis type 1 or 2 (NF), schwannomatosis); neuroendocrine carcinoma (such as gastroenteropancreatic neuroendocrine tumor (GEP-NET), carcinoid tumor); osteosarcoma (such as bone cancer); ovarian cancer (such as cystadenocarcinoma, ovarian embryonal carcinoma, ovarian adenocarcinoma); papillary adenocarcinoma; pancreatic cancer (such as pancreatic adenocarcinoma, intraductal papillary mucinous neoplasia (IPMN), islet cell tumor); parathyroid carcinoma; papillary adenocarcinoma; penile cancer (such as Paget's disease of the penis and scrotum); pharyngeal cancer; pinealoma; pituitary carcinoma; pleuropulmonary blastoma; primitive neuroectodermal tumor (PNT); plasmacytosis; paraneoplastic syndrome; intraepithelial neoplasia; prostate cancer (such as prostatic adenocarcinoma); rectal cancer; rhabdomyosarcoma; retinoblastoma; salivary gland carcinoma; skin cancer (such as squamous cell carcinoma (SCC), keratoacanthoma (KA), melanoma, basal cell carcinoma (BCC)); small intestine cancer (such as appendiceal cancer); soft tissue sarcoma (such as malignant fibrous histiocytoma (MFH), liposarcoma, malignant peripheral nerve sheath tumor (MPNST), chondrosarcoma, fibrosarcoma, myxosarcoma); sebaceous gland carcinoma; gastric cancer; small intestine cancer; sweat gland carcinoma; synovioma; testicular cancer (such as seminoma, testicular embryonal carcinoma); thymic carcinoma;Thyroid cancer (such as papillary thyroid cancer, papillary carcinoma of the thyroid (PTC), medullary thyroid cancer); urethral cancer; uterine cancer; vaginal cancer; and vulvar cancer (such as vulvar Paget's disease). See also US2019 / 0153098 by Goldberg et al.

[0156] In some embodiments, the cancer is a blood cancer (such as leukemia), liver cancer, lung cancer, lymphoma, melanoma, prostate cancer, head and neck cancer, bladder cancer, brain cancer, breast cancer, or cervical cancer. In some embodiments, the cancer is prostate cancer. In some embodiments, the cancer is head and neck cancer. In some embodiments, the cancer is ovarian cancer. In some embodiments, the cancer is cervical cancer. In some embodiments, the cancer is malignant mesothelioma.

[0157] In some embodiments, the cancer has PRX3 expression. For example, the cancer can be a cancer type that is generally known to express PRX3 and / or the cancer is determined (e.g., by testing a biopsy) to have PRX3 expression.

[0158] The cancer can be metastatic, where cancer cells from a primary or original tumor migrate to another organ or tissue and can be identified as the tissue type of the primary or original tumor and not the tissue type of the organ or tissue in which the secondary (metastatic) tumor is located. As a non-limiting example, prostate cancer that has migrated to bone is called metastatic prostate cancer and includes cancerous prostate cells growing in bone tissue.

[0159] IV. Pharmaceutical Preparations

[0160] The active compounds disclosed herein, as noted above, can be prepared in the form of their pharmaceutically acceptable salts. Pharmaceutically acceptable salts are salts that retain the desired biological activity of the parent compound and do not impart undesired toxicological effects. Examples of such salts are (a) acid addition salts formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, nitric acid, etc.; and salts formed with organic acids such as acetic acid, oxalic acid, tartaric acid, succinic acid, maleic acid, fumaric acid, gluconic acid, citric acid, malic acid, ascorbic acid, benzoic acid, tannic acid, palmitic acid, alginic acid, polyglutamic acid, naphthalenesulfonic acid, methanesulfonic acid, p-toluenesulfonic acid, naphthalenedisulfonic acid, polygalacturonic acid, and the like; (b) salts formed from elemental anions such as chlorine, bromine, and iodine; and (c) salts derived from bases such as ammonium salts, alkali metal salts such as sodium and potassium salts, alkaline earth metal salts such as calcium and magnesium salts, and salts with organic bases such as dicyclohexylamine and N-methyl-D-glucamine.

[0161] The active compounds of the present invention can be prepared as pharmaceutically acceptable prodrugs. Such prodrugs are those which, within the scope of sound medical judgment, are suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable risk / benefit ratio, and effective for their intended use, and, where possible, are zwitterionic forms of the compounds of the present invention. The term "prodrug" refers to a compound that is rapidly transformed in vivo, for example by hydrolysis in the blood, to produce the parent compound of the above formula. A thorough discussion is provided in Volume 14 of T. Higuchi and V. Stella, Prodrugs as Novel Delivery Systems, the A.C.S. Symposium Series and Edward B. Roche, Bioreversible Carriers in Drug Design, American Pharmaceutical Association and Pergamon Press, 1987, which are hereby incorporated by reference herein. See also U.S. Patent No. 6,680,299. Examples include prodrugs that are metabolized in vivo by a subject to an active drug having the activity of the active compound as described herein, where the prodrug is an ester of an alcohol or carboxylic acid group (if such groups are present in the compound); an acetal or ketal of an alcohol group (if such a group is present in the compound); an N-Mannich base or imine of an amine group (if such a group is present in the compound); or a Schiff base, oxime, acetal, enol ester, oxazolidine, or thiazolidine of a carbonyl group (if such a group is present in the compound), as described, for example, in U.S. Patent No. 6,680,324 and U.S. Patent No. 6,680,322.

[0162] The active compounds described above can be formulated for administration in a pharmaceutical carrier according to known techniques. See, for example, Remington, The Science and Practice of Pharmacy (9th Edition, 1995). In the manufacture of a pharmaceutical formulation according to the present invention, the active compound (including its physiologically acceptable salts) is typically admixed with a carrier that is especially acceptable. Of course, the carrier must be acceptable in the sense of being compatible with any other ingredients in the formulation and must be harmless to the patient. The carrier can be solid or liquid or both, and is preferably formulated with the compound as a unit dosage form, such as a tablet, which can contain from 0.01% or 0.5% to 95% or 99% by weight of the active compound. One or more active compounds can be incorporated into the formulations of the present invention, and the formulations can be prepared by any well-known pharmaceutical technique, which includes admixing the components, optionally including one or more auxiliary ingredients.

[0163] The formulations of the present invention include those suitable for oral, rectal, topical, buccal (e.g., sublingual), vaginal, parenteral (e.g., subcutaneous, intramuscular, intradermal or intravenous), local (i.e., both skin and mucosal surfaces, including airway surfaces) and transdermal administration, but the most suitable route in any given case will depend on the nature, severity and site of the condition being treated and the nature of the particular active compound being used.

[0164] Formulations suitable for oral administration may be presented in discrete units such as capsules, cachets, lozenges or tablets, each containing a predetermined amount of the active compound; as a powder or granules; as a solution or suspension in an aqueous or non-aqueous liquid; or as an oil-in-water or water-in-oil emulsion. Such formulations may be prepared by any suitable pharmaceutical method, which includes the step of bringing the active compound into association with a suitable carrier (which may contain one or more accessory ingredients as noted above). In general, the formulations of the present invention are prepared by uniformly and intimately admixing the active compound with a liquid carrier and / or a finely divided solid carrier and then, if necessary, shaping the resulting mixture. For example, tablets may be prepared by compressing or molding a powder or granules containing the active compound and, optionally, one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the compound in a free-flowing form, such as a powder or granules optionally mixed with a binder, lubricant, inert diluent and / or surfactant / dispersant. Molded tablets may be prepared by molding in a suitable machine a powdered compound moistened with an inert liquid binder.

[0165] Formulations suitable for buccal (e.g., sublingual) administration include lozenges, which contain the active compound in a flavored base, which is usually sucrose and gum arabic or tragacanth; and pastilles, which contain the compound in an inert base such as gelatin and glycerin or sucrose and gum arabic.

[0166] The pharmaceutical compositions of the present invention suitable for parenteral administration include sterile aqueous and non-aqueous injection solutions of the active compounds, which are preferably isotonic with the blood of the intended recipient. These compositions may contain antioxidants, buffers, bacteriostats and solutes rendering the compositions isotonic with the blood of the intended recipient. Aqueous and non-aqueous sterile suspensions may include suspending and thickening agents. The compositions may be presented in unit / dose or multi-dose containers, for example, sealed ampoules and vials, and may be stored under lyophilized (freeze-dried) conditions, requiring only the addition of a sterile liquid carrier, such as saline or water for injection, immediately prior to use. The temporary injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the previously described type. For example, in one aspect of the present invention, there is provided an injectable stable sterile composition comprising the active compound or its salt in unit dosage form in a sealed container. The compound or salt is provided in the form of a lyophilizate capable of being reconstituted with a suitable pharmaceutically acceptable carrier to form a liquid composition suitable for injection into a subject. The unit dosage form typically contains from about 10 mg to about 10 g of the compound or salt. When the compound or salt is substantially insoluble in water, a sufficient amount of a physiologically acceptable emulsifier may be used in an amount sufficient to emulsify the compound or salt in an aqueous carrier. One such useful emulsifier is phosphatidylcholine.

[0167] The pharmaceutical compositions suitable for rectal administration are preferably presented as unit dose suppositories. These may be prepared by admixing the active compound with one or more conventional solid carriers, such as cocoa butter, and then shaping the resulting mixture.

[0168] The pharmaceutical compositions suitable for topical application to the skin preferably take the form of ointments, creams, lotions, pastes, gels, sprays, aerosols or oils. Carriers which may be used include petrolatum, lanolin, polyethylene glycols, alcohols, transdermal penetration enhancers and combinations of two or more thereof.

[0169] The pharmaceutical compositions suitable for transdermal administration may be presented as discrete patches adapted to remain in intimate contact with the epidermis of the recipient for an extended period of time. The pharmaceutical compositions suitable for transdermal administration may also be delivered by iontophoresis (see, for example, Pharmaceutical Research 3(6):318 (1986)), and typically take the form of an optionally buffered aqueous solution of the active compound. Suitable compositions include citrate or bis / tris buffers (pH 6) or ethanol / water and contain 0.1 - 0.2 M of the active ingredient.

[0170] In addition, the present invention provides liposomal formulations of the compounds and their salts disclosed herein. Techniques for forming liposomal suspensions are well known in the art. When the compound or its salt is a water-soluble salt, using conventional liposome techniques, it can be incorporated into lipid vesicles. In such cases, due to the water solubility of the compound or salt, the compound or salt will be substantially entrapped within the hydrophilic center or core of the liposome. The lipid layer employed can be of any conventional composition and can contain cholesterol or can be cholesterol-free. When the compound or salt of interest is water-insoluble, again using conventional liposome-forming techniques, the salt can be substantially entrapped within the hydrophobic lipid bilayer that forms the liposome structure. In either case, the size of the resulting liposomes can be reduced, for example, by using standard sonication and homogenization techniques. The liposomal formulations containing the compounds or their salts disclosed herein can be lyophilized to produce a lyophilizate, which can be reconstituted with a pharmaceutically acceptable carrier such as water to regenerate the liposomal suspension.

[0171] Other pharmaceutical compositions can be prepared from the compounds or their salts disclosed herein, such as aqueous emulsions. In such cases, the composition will contain a sufficient amount of a pharmaceutically acceptable emulsifier to emulsify the desired amount of the compound or salt. Particularly useful emulsifiers include phosphatidylcholine and lecithin.

[0172] In addition to the active compound, the pharmaceutical composition can also contain other additives, such as pH-adjusting additives. Specifically, useful pH regulators include acids, such as hydrochloric acid; bases or buffers, such as sodium lactate, sodium acetate, sodium phosphate, sodium citrate, sodium borate, or sodium gluconate. In addition, the composition can contain microbial preservatives. Useful microbial preservatives include methylparaben, propylparaben, and benzyl alcohol. Microbial preservatives are typically employed when the formulation is placed in a vial designed for multi-dose use. If desired, the pharmaceutical compositions of the present invention can be lyophilized using techniques well known in the art.

[0173] V. Dosage and Routes of Administration

[0174] As noted above, the present invention provides pharmaceutical formulations containing the active compound (including its pharmaceutically acceptable salts) in a pharmaceutically acceptable carrier for oral, rectal, topical, buccal, parenteral, intrapleural, intraovarian, intramuscular, intradermal, intravascular, and / or transdermal administration. Parenteral administration can be, for example, intravascular (intravenous or intraarterial), intrapleural, intraperitoneal, or intraovarian administration by injection, infusion, or implantation.

[0175] The therapeutically effective dose of any particular compound within the scope of the present invention will vary somewhat from compound to compound and from patient to patient and will depend upon the condition of the patient and the route of administration. As a general proposition, doses in the range of about 0.1 mg / kg to about 50 mg / kg are expected to have therapeutic efficacy, where all weights are calculated based on the weight of the active compound, including cases where salts are employed. Toxicity concerns at higher levels may limit intravenous doses to lower levels, e.g., up to about 10 mg / kg, where all weights are calculated based on the weight of the active moiety, including cases where salts are employed. Doses in the range of about 10 mg / kg to about 50 mg / kg may be used for oral administration. Typically, doses in the range of about 0.5 mg / kg to 5 mg / kg may be used for intramuscular injection.

[0176] Depending on the condition being treated, the compounds described herein may be administered alone or in combination with one or more additional active agents useful in treating the disease or condition afflicting the patient. Examples of additional active agents include, but are not limited to, those shown in paragraphs 0065 to 0387 of U.S. Patent Application Publication No. 20050181977 (published Aug. 18, 2005) to W. Hunter, D. Gravett, et al. (assigned to Angiotech International AG), the disclosure of which is incorporated herein by reference in its entirety.

[0177] The present invention is explained in more detail in the following non-limiting examples. Examples

[0178] We have identified the minimal fragment of the TS of PRX3 that covalently modifies, crosslinks, and inactivates PRX3. In addition, compounds based on this fragment inhibit PRX3, can be specific for PRX3 as compared to other human PRX isoforms, kill multiple cancer cell types in culture, and are effective in a mouse model of malignant mesothelioma.

[0179] Abbreviations

[0180] mmole: millimole

[0181] g: gram

[0182] mL: milliliter

[0183] HOBt.H2O: 1-Hydroxybenzotriazole hydrate

[0184] EDC.HCl: 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride

[0185] HCl: Hydrochloric acid

[0186] DCM: Dichloromethane or methylene chloride

[0187] DBU: 1,8 - Diazabicyclo[5.4.0]undec - 7 - ene

[0188] (i - Pr)2Net, DIPEA: N,N - Diisopropylethylamine

[0189] NMM: 4 - Methylmorpholine

[0190] Et3N: Triethylamine

[0191] THF: Tetrahydrofuran

[0192] TBAF: Tetrabutylammonium fluoride

[0193] DMA: N,N - Dimethylacetamide

[0194] 4 - DMAP: 4 - Dimethylaminopyridine

[0195] TBAI: Tetrabutylammonium iodide

[0196] CDI: N,N’ - Carbonyldiimidazole

[0197] DCC: N,N’ - Dicyclohexylcarbodiimide

[0198] DME: 1,2 - Dimethoxyethane

[0199] TFAA: Trifluoroacetic anhydride

[0200] LAH, LiAlH4: Lithium aluminum hydride

[0201] TBTU: O - (Benzotriazol - 1 - yl) - N,N,N',N' - tetramethyluronium tetrafluoroborate

[0202] HATU: 1 - [Bis(dimethylamino)methylene] - 1H - 1,2,3 - triazolo[4,5 - b]pyridinium 3 - oxide hexafluorophosphate

[0203] DMF: N,N - Dimethylformamide

[0204] Aq.: Aqueous

[0205] RT: Room temperature

[0206] General synthetic procedures

[0207]

[0208]

[0209] General procedure

[0210] Example A: Dissolve thioamide (1.0 equiv) in ethanol (0.5 M solution). Add ethyl bromopyruvate (1.1 equiv), and heat the mixture to 80 °C until the reaction is complete by TLC analysis. Cool the mixture to room temperature and concentrate. Suspend the residue in saturated aqueous sodium bicarbonate (50 mL), and extract the mixture with ethyl acetate (3 x 20 mL). Dry the combined organics over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford Intermediate A.

[0211] Example B: Dissolve Intermediate A (1.0 equiv) in 4 / 1 / 1 THF / methanol / water. Add lithium hydroxide (3.0 equiv), and stir the mixture at room temperature until the reaction is complete by TLC analysis. Add water (25 mL), and treat the mixture with 1 N hydrochloric acid to pH = 4. Extract the resulting mixture with ethyl acetate (3 x 20 mL). Dry the combined organics over sodium sulfate, filter, and concentrate to afford the desired Intermediate B.

[0212] Example C: Dissolve Intermediate B (1.0 equiv) in DCM. Add L-serine methyl ester hydrochloride (1.2 equiv) then add N,N-diisopropylethylamine (2.0 equiv) and a coupling reagent (1.2 equiv). Stir the mixture at room temperature until the reaction is complete by TLC analysis. Add water (25 mL), and extract the mixture with DCM (3 x 15 mL). Dry the combined organics over sodium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford Intermediate C.

[0213] Example D: Dissolve Intermediate C in DCM. Add imidazole (1.2 equiv) then add tert-butyldimethylchlorosilane (1.2 equiv). Stir the reaction at room temperature until complete by TLC analysis. Add water (25 mL), and extract the mixture with DCM (3 x 15 mL). Dry the combined organics over sodium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography. Dissolve the isolated compound in 4 / 1 / 1 THF / methanol / water. Add lithium hydroxide (3.0 equiv), and stir the mixture at room temperature until the reaction is complete as judged by TLC. Add water (25 mL), and treat the solution with 1 N hydrochloric acid to pH = 3. Extract the mixture with ethyl acetate (3 x 15 mL). Dry the combined organics over sodium sulfate, filter, and concentrate to afford Intermediate D.

[0214] Example E: Intermediate D (1.0 eq) was dissolved in DCM, and L-serine methyl ester hydrochloride (1.2 eq) was added. N,N-Diisopropylethylamine (2.0 eq) was added and then the coupling reagent (1.2 eq) was added. The mixture was stirred at room temperature until the reaction was complete by TLC analysis. Water (25 mL) was added, and the mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography to afford Intermediate E.

[0215] Example F: Intermediate E (1.0 eq) was dissolved in DCM and cooled to 0 °C. Triethylamine (1.5 eq) was added and then methanesulfonyl chloride (1.5 eq) was added. The mixture was stirred at 0 °C until complete by TLC analysis. Water (25 mL) was added, and the mixture was extracted with DCM (3 x 15 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated. The residue was dissolved in THF and cooled to 0 °C. 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) (1.2 eq) was added, and the mixture was stirred at 0 °C until the reaction was complete by TLC analysis. Water (25 mL) was added, and the mixture was extracted with ethyl acetate (3 x 15 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated to afford the desired product. The residue (1.0 eq) was dissolved in THF. Tetrabutylammonium fluoride (1.1 eq, 1.0 M solution in THF) was added, and the solution was stirred at room temperature until the reaction was complete by TLC analysis. Water (25 mL) was added, and the mixture was extracted with ethyl acetate (3 x 15 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated. The isolated compound was dissolved in DCM and cooled to 0 °C. Triethylamine (1.5 eq) and methanesulfonyl chloride (1.5 eq) were added. The mixture was stirred at room temperature until the reaction was complete by TLC analysis. Water (25 mL) was added, and the mixture was extracted with DCM (3 x 15 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated. The residue was dissolved in THF and cooled to 0 °C. 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU, 1.2 eq) was added, and the mixture was stirred until complete by TLC analysis. Water (25 mL) was added, and the mixture was extracted with ethyl acetate (3 x 15 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography to afford the desired product.

[0216] N-(2-Bromothiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester

[0217]

[0218] 2-Bromothiazole-4-carboxylic acid (1.807 g, 8.69 mmol) was dissolved in DCM (17 mL). L-Serine methyl ester hydrochloride (1.643 g, 10.6 mmol) was added followed by N,N-diisopropylethylamine (3.00 mL, 17.2 mmol) and pyBOP (5.455 g, 10.5 mmol). The mixture was stirred at room temperature for 90 minutes. Water (50 mL) was added and the two layers were separated. The aqueous layer was extracted with DCM (2 x 15 mL). The combined organic layers were dried over sodium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography (Isco CombiPrep, 24 g RediSep column, 50 - 90% ethyl acetate / hexane gradient) to afford (2-bromothiazole-4-carbonyl)-L-serine methyl ester (3.224 g) as a white solid.

[0219] 1 H NMR (400 MHz, CDCl3) δ 8.08 (s, 1H), 8.04–7.93 (m, 1H), 4.84 (dt, J = 7.7, 3.8 Hz, 1H), 4.11 (dd, J = 11.3, 4.0 Hz, 1H), 4.03 (dd, J = 11.3, 3.6 Hz, 1H), 3.83 (s, 3H).

[0220] (2-Bromothiazole-4-carbonyl)-L-serine methyl ester (3.224 g) was dissolved in DCM (20 mL). Imidazole (0.854 g, 12.5 mmol) was added followed by tert-butyldimethylchlorosilane (1.891 g, 12.5 mmol), and the mixture was stirred at room temperature for 45 minutes. Water (50 mL) was added and the two layers were separated. The aqueous layer was extracted with DCM (2 x 15 mL). The combined organic layers were dried over sodium sulfate, filtered and concentrated. The crude product was purified by silica gel chromatography (Isco CombiPrep, 40 g Silicycle column, 10 - 40% ethyl acetate / hexane gradient) to afford N-(2-bromothiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (3.100 g, 84%) as a pale yellow oil.

[0221] 1 H NMR (400 MHz, CDCl3) δ 8.06 (s, 1H), 7.99–7.87 (m, 1H), 4.80 (dt, J = 8.6, 3.1 Hz, 1H), 4.17 (dd, J = 10.1, 2.9 Hz, 1H), 3.91 (dd, J = 10.1, 3.5 Hz, 1H), 3.78 (s, 3H), 0.90 (s, 9H), 0.06 (s, 3H), 0.05 (s, 3H).

[0222] Compound Synthesis

[0223] Compound 1: 4-(4-((3-((3-Methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2- yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylic acid tert-butyl ester

[0224] tert-Butyl 4-thiocarbamoylpiperidine-1-carboxylate (1.1)

[0225]

[0226] Dissolve 1-N-Boc-4-cyanopiperidine (2.005 g, 9.53 mmol) in pyridine (10 mL). Add triethylamine (1.50 mL, 10.7 mmol) and then add ammonium sulfide (40% aqueous solution, 1.80 mL, 10.5 mmol). Heat the mixture to 50 °C for 5 h, then cool to room temperature and concentrate. Dissolve the residue in ethyl acetate (50 mL). Wash the solution with 1 N hydrochloric acid (2 x 25 mL). Dry the organic matter over magnesium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography (Isco CombiPrep, 25 g Silicycle column, 30 - 60% ethyl acetate / hexane gradient) to afford tert-Butyl 4-thiocarbamoylpiperidine-1-carboxylate as a white solid (1.174 g, 50%).

[0227] 1 H NMR (400 MHz, chloroform-d) δ 7.51 (s, 1H), 6.94 (s, 1H), 4.18 (d, J = 37.0 Hz, 2H), 2.82–2.62 (m, 3H), 1.96–1.83 (m, 2H), 1.72 (dtd, J = 13.2, 12.3, 4.4 Hz, 2H), 1.46 (s, 9H).

[0228] 2-(1-(tert-Butoxycarbonyl)piperidin-4-yl)thiazole-4- Carboxylic Acid ethyl ester( 1.2)

[0229]

[0230] Dissolve tert-butyl 4-thiocarbamoylpiperidine-1-carboxylate (1.174 g, 4.80 mmol) in 1,4-dioxane (24 mL) and cool to 0 °C. Add potassium bicarbonate (3.868 g, 38.6 mmol) then add ethyl bromopyruvate (1.80 mL, 14.3 mmol). Stir the mixture at 0 °C for 4 h, then warm to room temperature and stir overnight. Concentrate the slurry to dryness and dissolve in a mixture of water (25 mL) and ethyl acetate (25 mL). Separate the two layers. Wash the organic layer with saturated aqueous sodium chloride (1 x 25 mL), dry over magnesium sulfate, filter and concentrate. Dissolve the residue in 1,4-dioxane (24 mL) and cool to 0 °C. Add pyridine (3.10 mL, 38.3 mmol) then add trifluoroacetic anhydride (2.70 mL, 19.4 mmol). Stir the mixture at 0 °C for 3 h, then warm to room temperature and stir for 2 h. Add triethylamine (16 mL), and concentrate the mixture. Dissolve the residue in ethyl acetate (40 mL), and wash successively with 0.5 N hydrochloric acid (2 x 50 mL), saturated aqueous sodium bicarbonate (1 x 25 mL) and saturated aqueous sodium chloride (1 x 25 mL). Dry the organic layer over magnesium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography (Isco CombiPrep, 25 g Silicycle column, 15-35% ethyl acetate / hexane gradient) to afford ethyl 2-(1-(tert-butoxycarbonyl)piperidin-4-yl)thiazole-4-carboxylate (1.704 g, 100% yield (quant.)), as a tan solid. 1 H NMR (400 MHz, chloroform-d) δ 8.08 (s, 1H), 4.42 (q, J = 7.1 Hz, 2H), 4.30–4.16 (m, 2H), 3.26 (tt, J = 11.8, 3.7 Hz, 1H), 2.85 (t, J = 13.0 Hz, 2H), 2.18–2.07 (m, 2H), 1.80–1.65 (m, 2H), 1.47 (s, 9H), 1.40 (t, J = 7.1 Hz, 3H).

[0231] 2-(1-(tert-Butoxycarbonyl)piperidin-4-yl)thiazole-4-carboxylic acid (1.3)

[0232]

[0233] Ethyl 2-(1-(tert-butoxycarbonyl)piperidin-4-yl)thiazole-4-carboxylate (1.704 g, 5.01 mmol) was dissolved in 4 / 1 / 1 THF / methanol / water (15 mL). Lithium hydroxide (0.484 g, 20.2 mmol) was added and the mixture was stirred at room temperature for 2 h and then concentrated to the aqueous layer. The solid was dissolved in water (200 mL) and the solution was treated with 1 N hydrochloric acid to pH = 3. The mixture was extracted with ethyl acetate (5 x 20 mL) and the combined organics were dried over sodium sulfate, filtered and concentrated to afford 2-(1-(tert-butoxycarbonyl)piperidin-4-yl)thiazole-4-carboxylic acid as a golden solid (1.451 g, 93%).

[0234] 1H NMR (400 MHz, chloroform-d) δ 8.20 (s, 1H), 4.23 (s, 2H), 3.23 (tt, J = 11.7, 3.8 Hz, 1H), 2.88 (t, J = 12.7 Hz, 2H), 2.20–2.08 (m, 2H), 1.84–1.67 (m, 2H), 1.48 (s, 9H).

[0235] (S)-tert-Butyl 4-(4-((3-hydroxy-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (1.4)

[0236]

[0237] 2-(1-(tert-butoxycarbonyl)piperidin-4-yl)thiazole-4-carboxylic acid (1.451 g, 4.64 mmol) was dissolved in DCM (9 mL). L-Serine methyl ester hydrochloride (0.870 g, 5.59 mmol) was added, then N,N-diisopropylethylamine (2.40 mL, 13.8 mmol) and BOP reagent (2.475 g, 5.60 mmol) were added in sequence. The mixture was stirred overnight at room temperature and water (50 mL) was added. The two layers were separated and the aqueous layer was extracted with DCM (3 x 20 mL). The combined organics were dried over sodium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford (S)-tert-butyl 4-(4-((3-hydroxy-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate as a thick yellow gel (1.763 g, 92%).

[0238] 11H NMR (400 MHz, chloroform-d) δ 8.12 (d, J = 7.5 Hz, 1H), 8.02 (s, 1H), 4.84 (dt, J = 7.6, 3.8 Hz, 1H), 4.21 (s, 2H), 4.11–4.01 (m, 2H), 3.83 (s, 3H), 3.14 (tt, J = 11.6, 3.7 Hz, 1H), 2.89 (t, J = 12.4 Hz, 2H), 2.65 (t, J = 6.1 Hz, 1H), 2.17–2.07 (m, 2H), 1.75 (qd, J = 12.4, 4.3 Hz, 2H), 1.48 (s, 9H).

[0239] tert-Butyl 4-(4-((3-methoxy-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (1.5)

[0240]

[0241] Dissolve (S)-tert-butyl 4-(4-((3-hydroxy-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (1.763 g, 4.26 mmol) in DCM (9 mL) and cool to 0 °C. Add methanesulfonyl chloride (0.365 mL, 4.72 mmol), then dropwise add triethylamine (0.700 mL, 4.99 mmol). Stir the mixture at 0 °C for 60 minutes and add water (50 mL). Separate the two layers and extract the aqueous layer with DCM (2 x 15 mL). Dry the combined organic layers over sodium sulfate, filter, and concentrate. Dissolve the residue in THF (9 mL) and cool to 0 °C. Dropwise add 1,8-diazabicyclo[5.4.0]undec-7-ene (0.700 mL, 4.68 mmol) and stir the solution at 0 °C for 90 minutes, then at room temperature overnight. Add water (50 mL) and extract the mixture with ethyl acetate (3 x 15 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford tert-butyl 4-(4-((3-methoxy-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (1.227 g, 73%) as a white solid.

[0242] 11H NMR (400 MHz, chloroform-d) δ 9.69 (s, 1H), 8.05 (s, 1H), 6.76 (s, 1H), 5.98 (d, J = 1.6 Hz, 1H), 4.32–4.13 (m, 2H), 3.90 (s, 3H), 3.16 (tt, J = 11.6, 3.8 Hz, 1H), 2.90 (t, J = 12.7 Hz, 2H), 2.21–2.08 (m, 2H), 1.76 (dtd, J = 13.1, 11.8, 4.3 Hz, 2H).

[0243] 2-(2-(1-(tert-Butoxycarbonyl)piperidin-4-yl)thiazole-4-carboxamido)acrylic acid (1.6)

[0244]

[0245] Using the procedure described in Example 1.3, tert-butyl 4-(4-((3-methoxy-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (1.227 g, 3.10 mmole) was converted to 2-(2-(1-(tert-butoxycarbonyl)piperidin-4-yl)thiazole-4-carboxamido)acrylic acid (1.130 g, 96%) as a pale yellow solid.

[0246] 1 1H NMR (400 MHz, DMSO-d6) δ 9.65 (s, 1H), 8.36 (s, 1H), 6.52 (s, 1H), 5.82 (d, J = 1.5 Hz, 1H), 4.03 (d, J = 13.1 Hz, 2H), 3.38–3.24 (m, 1H), 2.09–2.01 (m, 2H), 1.66–1.50 (m, 2H), 1.41 (s, 9H).

[0247] (S)-tert-Butyl 4-(4-((3-((3-hydroxy-1-methoxy-1-oxopropan-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (1.7)

[0248]

[0249] 2-(2-(1-(tert-Butoxycarbonyl)piperidin-4-yl)thiazole-4-carboxamido)acrylic acid (0.706 g, 1.85 mmol) was suspended in DCM (6 mL). L-Serine methyl ester hydrochloride (0.408 g, 2.62 mmol) was added followed by N,N-diisopropylethylamine (0.970 mL, 5.57 mmol). Propylphosphonic anhydride (50% solution in 2-MeTHF, 0.650 mL, 2.22 mmol) was added and the mixture was stirred at room temperature for 90 minutes. The solution was loaded onto a silica column and purified by silica chromatography (Isco CombiPrep, 25 g Silicycle column, 60 - 90% ethyl acetate / hexane gradient) to afford tert-butyl (S)-4-(4-((3-((3-hydroxy-1-methoxy-1-oxopropan-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (0.310 g, 35%).

[0250] 1 H NMR (400 MHz, chloroform-d) δ 9.85 (s, 1H), 8.05 (s, 1H), 7.08 (d, J = 7.3 Hz, 1H), 6.64 (d, J = 1.9 Hz, 1H), 5.48 (t, J = 1.6 Hz, 1H), 4.76 (dt, J = 7.0, 3.4 Hz, 1H), 4.20 (s, 2H), 4.12–4.00 (m, 2H), 3.84 (s, 3H), 3.14 (tq, J = 11.8, 4.1 Hz, 1H), 2.88 (t, J = 12.7 Hz, 2H), 2.49 (s, 1H), 2.21–2.08 (m, 2H), 1.75 (dtd, J = 13.3, 11.8, 4.3 Hz, 2H), 1.48 (s, 9H).

[0251] tert-Butyl 4-(4-((3-((3-methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (1)

[0252]

[0253] (S)-tert-Butyl 4-(4-((3-((3-hydroxy-1-methoxy-1-oxopropan-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (0.310 g, 0.808 mmol) was dissolved in DCM (1.6 mL) and cooled to 0 °C. Methanesulfonyl chloride (0.070 mL, 0.904 mmol) was added followed by triethylamine (0.125 mL, 0.892 mmol). The solution was stirred at 0 °C for 90 minutes and water (25 mL) was added. The mixture was extracted with DCM (3 x 15 mL). The combined organics were dried over sodium sulfate, filtered and concentrated. The residue was dissolved in THF (1.6 mL) and cooled to 0 °C. 1,8-Diazabicyclo[5.4.0]undec-7-ene (0.145 mL, 0.970 mmol) was added and the mixture was stirred at 0 °C for 60 minutes. Water (25 mL) was added and the mixture was extracted with ethyl acetate (3 x 15 mL). The combined organics were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography (Isco CombiPrep, 12 g RediSep Gold column, 20 - 40% ethyl acetate / hexane gradient) to afford tert-butyl 4-(4-((3-((3-methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (0.249 g, 66%) as a white solid.

[0254] 1H NMR (400 MHz, chloroform-d) δ 9.89 (s, 1H), 8.54 (s, 1H), 8.06 (s, 1H), 6.75 (d, J = 2.2 Hz, 1H), 6.69 (s, 1H), 6.02 (d, J = 1.1 Hz, 1H), 5.47 (t, J = 1.9 Hz, 1H), 4.22 (s, 2H), 3.90 (s, 3H), 3.17 (tt, J = 11.6, 3.7 Hz, 1H), 2.89 (t, J = 12.7 Hz, 2H), 2.14 (d, J = 13.1 Hz, 2H), 1.84–1.68 (m, 2H), 1.49 (s, 9H).

[0255] Compound 2: 2-(2-(2-(6-((tert-Butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carboxamido)acryloyl amino)methyl acrylate

[0256] tert-Butyl 2-(tert-butoxycarbonyl)amino-5-cyanopyridinecarbamate (2.1)

[0257]

[0258] 2-Amino-5-cyanopyridine (3.010 g, 25.3 mmol) was dissolved in DCM (30 mL). Triethylamine (7.00 mL, 49.9 mmol) and 4-dimethylaminopyridine (0.305 g, 0.250 mmol) were added. Di-tert-butyl dicarbonate (11.013 g, 50.5 mmol) was added and the solution was stirred at room temperature for 24 h. Water (100 mL) was added and the two layers were separated. The aqueous layer was extracted with DCM (2 x 30 mL). The combined organics were washed with saturated aqueous sodium chloride (1 x 50 mL), then dried over sodium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography (Isco CombiPrep, 40 g Silicycle column, 10-25% ethyl acetate / hexane gradient) to afford tert-butyl 2-(tert-butoxycarbonyl)amino-5-cyanopyridinecarbamate (7.185 g, 89%) as a white solid.

[0259] 1 H NMR (400 MHz, chloroform-d) δ 8.66 (dd, J = 2.3, 0.8 Hz, 1H), 7.95 (dd, J = 8.6, 2.3 Hz, 1H), 7.67 (dd, J = 8.6, 0.8 Hz, 1H), 1.51 (s, 18H).

[0260] 2-(Bis(N-tert-butoxycarbonyl)amino)-5-(thiocarboxamido)pyridine (2.2)

[0261]

[0262] Tert-butyl 2-(tert-butoxycarbonyl)amino-5-cyanopyridinecarbamate (4.994 g, 15.6 mmol) was dissolved in pyridine (16 mL). Triethylamine (2.40 mL, 17.1 mmol) and ammonium sulfide (40% aqueous solution, 3.20 mL, 18.7 mmol) were then added and the mixture was heated to 50 °C for 7 h. The mixture was cooled to room temperature and concentrated. The residue was dissolved in ethyl acetate (50 mL) and washed with water (2 x 25 mL) and brine (1 x 25 mL). The organics were dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography (Is co CombiPrep, 40 g Silicycle column, 10-30% ethyl acetate / hexane gradient) to afford 2-(bis(N-tert-butoxycarbonyl)amino)-5-(thiocarboxamido)pyridine (6.353 g) as a yellow solid.

[0263] 11H NMR (400 MHz, chloroform-d) δ 8.86 (dd, J = 2.6, 0.8 Hz, 1H), 8.28 (dd, J = 8.5, 2.6 Hz, 1H), 7.83–7.69 (m, 1H), 7.54 (s, 1H), 7.42 (dd, J = 8.5, 0.8 Hz, 1H), 1.49 (s, 18H).

[0264] Ethyl 2-(4-(bis(tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carboxylate (2.3)

[0265]

[0266] Dissolve 2-(bis-N-tert-butoxycarbonyl)amino)-5-(thiocarboxamido)pyridine (6.353 g, 18.0 mmole) in 1,4-dioxane (90 mL) and cool to 0 °C. Add potassium bicarbonate (14.574 g, 146 mmole), then slowly add ethyl bromopyruvate (4.50 mL, 35.9 mmole). Stir the mixture at 0 °C for 4 h, then warm to room temperature and allow to stir overnight. Concentrate the mixture and suspend the residue in ethyl acetate (100 mL). Wash the mixture successively with water (2 x 50 mL) and saturated aqueous sodium chloride (1 x 50 mL). Dry the organic layer over magnesium sulfate, filter and concentrate. Dissolve the residue in 1,4-dioxane (90 mL) and cool to 0 °C. Add pyridine (11.6 mL, 143 mmole), then slowly add trifluoroacetic anhydride (5.00 mL, 36.0 mmole). Stir the dark red mixture at 0 °C for 3 h, then at room temperature for 2 h. Add triethylamine (30 mL) and concentrate the mixture. Suspend the residue in ethyl acetate (75 mL) and wash successively with 0.5 N hydrochloric acid (3 x 50 mL) and saturated aqueous sodium bicarbonate (1 x 25 mL). Dry the organic layer over magnesium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography (Isco CombiPrep, 40 g Silicycle column, 10–30% ethyl acetate / hexane gradient) to afford ethyl 2-(4-(bis(tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carboxylate (6.302 g, 78%) as a yellow solid.

[0267] 11H NMR (400 MHz, chloroform-d) δ 9.02 (dd, J = 2.4, 0.8 Hz, 1H), 8.37 (dd, J = 8.4, 2.5 Hz, 1H), 8.22 (s, 1H), 7.44 (dd, J = 8.4, 0.8 Hz, 1H), 4.46 (qd, J = 7.1, 3.9 Hz, 2H), 1.47 (s, 18H), 1.44 (td, J = 7.1, 2.3 Hz, 3H).

[0268] 2-(6-((tert-Butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carboxylic acid (2.4)

[0269]

[0270] Using the procedure described for Example 1.3, ethyl 2-(4-(bis(tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carboxylate (6.302 g, 14.0 mmole) was converted to 2-(6-((tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carboxylic acid (3.323 g, 74%) as a white solid.

[0271] 1 1H NMR (400 MHz, DMSO-d6) δ 10.20 (s, 1H), 8.83 (dd, J = 2.5, 0.8 Hz, 1H), 8.49 (s, 1H), 8.29 (dd, J = 8.8, 2.5 Hz, 1H), 7.97 (dd, J = 8.8, 0.8 Hz, 1H), 1.49 (s, 9H).

[0272] (2-(6-((tert-Butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carbonyl)-L-serine methyl ester (2.5)

[0273]

[0274] Using the procedure described for Example 1.4, 2-(6-((tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carboxylic acid (3.323 g, 10.3 mmole) was converted to (2-(6-((tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carbonyl)-L-serine methyl ester (6.065 g) as a white solid.

[0275] 1H NMR (400 MHz, chloroform-d) δ 8.79 (dd, J = 2.3, 0.8 Hz, 1H), 8.62 (s, 1H), 8.25–8.14 (m, 2H), 8.14–8.05 (m, 2H), 4.88 (dt, J = 7.6, 3.7 Hz, 1H), 4.20–4.08 (m, 2H), 3.85 (s, 3H), 1.57 (s, 9H).

[0276] N-(2-(6-((tert-Butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (2.6)

[0277]

[0278] Dissolve methyl 2-(6-((bis(tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carbonyl)-L-serinate (1.723 g, 3.30 mmole) in DMF (6.5 mL). Add tert-butyldimethylchlorosilane (0.551 g, 3.66 mmole) then add imidazole (0.274 g, 4.02 mmole), and stir the solution at room temperature for 90 minutes. Add water (50 mL), and extract the mixture with diethyl ether (3 x 20 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford methyl O-(tert-butyldimethylsilyl)-N-(6-((bis(tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carbonyl)-L-serinate (1.711 g, 81%) as a colorless oil.

[0279] Dissolve methyl O-(tert-butyldimethylsilyl)-N-(6-((bis(tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carbonyl)-L-serinate (1.711 g, 2.69 mmole) in 4 / 1 / 1 THF / methanol / water (9 mL). Add lithium hydroxide (0.322 g, 13.4 mmole), and stir the mixture at room temperature for 2 hours, then concentrate to the aqueous layer. Suspend the residue in water (50 mL), and treat the mixture with 1 N hydrochloric acid to pH = 3. Extract the resulting mixture with ethyl acetate (4 x 20 mL). Dry the combined organic layers over sodium sulfate, filter, and concentrate to afford N-(2-(6-((tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (4.856 g, 100%) as a white foam solid.

[0280] 11H NMR (400 MHz, DMSO-d6) δ 10.28 (s, 1H), 8.92 (dd, J = 2.5, 0.8 Hz, 1H), 8.43 (s, 1H), 8.33 (dd, J = 8.8, 2.5 Hz, 1H), 8.22 (d, J = 8.6 Hz, 1H), 8.01 (dd, J = 8.8, 0.8 Hz, 1H), 4.64 (dt, J = 8.6, 3.6 Hz, 1H), 4.15 (dd, J = 10.3, 3.6 Hz, 1H), 4.00 (dd, J = 10.3, 3.7 Hz, 1H), 1.54 (s, 9H), 0.92 (s, 9H), 0.10 (s, 3H), 0.08 (s, 3H).

[0281] N-(2-(6-((tert-Butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester ( 2.7)

[0282]

[0283] Using the general procedure described for Example 1.4, N-(2-(6-((tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (3.010 g, 5.76 mmol) was converted to N-(2-(6-((tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester as a white solid (3.276 g, 91%).

[0284] 1 1H NMR (400 MHz, chloroform-d) δ 8.82–8.75 (m, 1H), 8.25–8.16 (m, 2H), 8.12 (d, J = 5.6 Hz, 1H), 8.06 (dt, J = 8.8, 1.1 Hz, 1H), 7.85 (d, J = 19.8 Hz, 1H), 7.46 (d, J = 7.3 Hz, 1H), 4.74–4.61 (m, 2H), 4.20 (dd, J = 9.8, 4.1 Hz, 1H), 4.06–3.93 (m, 2H), 3.86 (ddd, J = 9.8, 8.3, 6.3 Hz, 1H), 3.78 (s, 3H), 1.56 (s, 9H), 0.94 (s, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[0285] Methyl 2-(2-(2-(6-((tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carboxamido)acrylamido)acrylate (2)

[0286]

[0287] Dissolve N-(2-(6-((tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (1.148 g, 1.84 mmol) in DCM (4 mL) and cool to 0 °C. Add methanesulfonyl chloride (0.160 mL, 2.07 mmol) and then add triethylamine (0.290 mL, 2.07 mmol). Stir the mixture at 0 °C for 90 minutes and add water (50 mL). Extract the mixture with DCM (3 x 15 mL). Dry the combined organic layers over sodium sulfate, filter and concentrate. Dissolve the residue in THF (4 mL) and cool to 0 °C. Add 1,8-diazabicyclo[5.4.0]undec-7-ene (0.300 mL, 2.01 mmol) and stir the solution at 0 °C for 2 hours, then warm to room temperature and stir overnight. Add water (50 mL) and extract the mixture with ethyl acetate (3 x 15 mL). Dry the combined organic layers over magnesium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography to afford methyl (S)-2-(2-(2-(6-((tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carboxamido)-3-((tert-butyldimethylsilyl)oxy)propanamido)acrylate (0.838 g, 75%).

[0288] Dissolve methyl (S)-2-(2-(2-(6-((tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carboxamido)-3-((tert-butyldimethylsilyl)oxy)propanamido)acrylate (0.838 g, 1.38 mmol) in THF (2.8 mL) and cool to 0 °C. Add tetrabutylammonium fluoride (1.0 M solution in THF, 1.55 mL, 1.55 mmol) and stir the solution at 0 °C for 4 hours. Add water (50 mL) and extract the two layers with ethyl acetate (3 x 15 mL). Dry the combined organic layers over magnesium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography to afford the desired product as a white solid (0.558 g, 82%).

[0289] Using the dehydration procedure described above, methyl (S)-2-(2-(2-(6-((tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carboxamido)-3-hydroxypropanamido)acrylate (0.558 g, 1.14 mmol) was converted to methyl 2-(2-(2-(6-((tert-butoxycarbonyl)amino)pyridin-3-yl)thiazole-4-carboxamido)acrylamide)acrylate (0.162 g, 19%) as a white solid.

[0290] 1 H NMR (400 MHz, chloroform-d) δ 10.03–9.93 (m, 1H), 8.91 (dd, J = 2.4, 0.8 Hz, 1H), 8.55 (s, 1H), 8.32 (s, 1H), 8.25 (ddd, J = 8.8, 2.4, 0.5 Hz, 1H), 8.15 (s, 1H), 8.10 (dd, J = 8.8, 0.8 Hz, 1H), 6.78 (d, J = 2.3 Hz, 1H), 6.71 (s, 1H), 6.03 (d, J = 1.3 Hz, 1H), 5.51 (t, J = 1.9 Hz, 1H), 3.91 (s, 3H), 1.56 (s, 9H).

[0291] Compound 3: 3-(4-((3-((3-Methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2- yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylic acid tert-butyl ester

[0292] tert-Butyl 3-(4-(((S)-3-((tert-butyldimethylsilyl)oxy)-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (3.1)

[0293]

[0294] Using the procedure described for Example 1, 1-N-tert-butoxycarbonyl-3-cyanopiperidine (2.505 g, 11.9 mmol) was converted to tert-butyl 3-(4-(((S)-3-((tert-butyldimethylsilyl)oxy)-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (1.002 g).

[0295] 11H NMR (400 MHz, chloroform-d) δ 8.08 (d, J = 8.7 Hz, 1H), 8.01 (s, 1H), 4.88–4.78 (m, 1H), 4.30 (q, J = 7.1 Hz, 1H), 4.23–4.14 (m, 1H), 4.01 (d, J = 13.3 Hz, 1H), 3.92 (dd, J = 10.1, 3.5 Hz, 1H), 3.78 (s, 3H), 3.14 (dt, J = 10.6, 6.1 Hz, 2H), 2.97–2.82 (m, 1H), 2.27–2.15 (m, 1H), 1.90–1.73 (m, 2H), 1.63 (s, 1H), 1.48 (s, 9H), 0.89 (s, 9H), 0.06 (s, 3H), 0.04 (s, 3H).

[0296] N-(2-(1-(tert-Butoxycarbonyl)piperidin-3-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (3.2)

[0297]

[0298] Using the procedure described for Example 1.3, tert-butyl 3-(4-(((S)-3-((tert-butyldimethylsilyl)oxy)-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (1.002 g, 1.90 mmole) was converted to N-(2-(1-(tert-butoxycarbonyl)piperidin-3-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (1.041 g) as a colorless oil.

[0299] 1 1H NMR (400 MHz, chloroform-d) δ 8.13 (d, J = 8.2 Hz, 1H), 8.06 (d, J = 7.4 Hz, 1H), 4.90–4.79 (m, 1H), 4.41–4.27 (m, 1H), 4.24 (dd, J = 10.1, 3.0 Hz, 1H), 4.08–3.98 (m, 1H), 3.95 (dd, J = 10.1, 4.0 Hz, 1H), 3.21–3.00 (m, 2H), 2.98–2.83 (m, 1H), 2.28–2.14 (m, 1H), 1.89–1.72 (m, 2H), 1.60 (d, J = 20.6 Hz, 1H), 1.47 (s, 10H), 0.90 (s, 9H), 0.08 (d, J = 2.3 Hz, 6H).

[0300] tert-Butyl 3-(4-(((4S,7S)-4-(hydroxymethyl)-10,10,11,11-tetramethyl-3,6-dioxo-2,9-dioxa-5-aza-10-sila-dodecan-7-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (3.3)

[0301]

[0302] Using the general procedure described for Example 1.4, N-(2-(1-(tert-butoxycarbonyl)piperidin-3-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (1.041 g, 2.03 mmole) was converted to tert-butyl 3-(4-(((4S,7S)-4-(hydroxymethyl)-10,10,11,11-tetramethyl-3,6-dioxo-2,9-dioxa-5-aza-10-sila-dodecan-7-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (0.728 g, 58%) as a colorless oil. 1 1H NMR (400 MHz, chloroform-d) δ 8.12 (d, J = 7.0 Hz, 1H), 8.06–7.98 (m, 1H), 7.44 (d, J = 7.2 Hz, 1H), 4.68 (dt, J = 7.3, 3.7 Hz, 1H), 4.66–4.57 (m, 1H), 4.21–4.15 (m, 1H), 3.99 (t, J = 7.7 Hz, 3H), 3.84 (dtd, J = 9.8, 6.9, 1.2 Hz, 1H), 3.78 (d, J = 4.6 Hz, 3H), 3.14 (s, 2H), 2.99–2.83 (m, 2H), 2.28–2.13 (m, 1H), 1.90–1.73 (m, 3H), 1.60 (t, J = 11.8 Hz, 1H), 1.47 (d, J = 3.2 Hz, 9H), 0.92 (s, 9H), 0.13 (s, 3H), 0.12 (s, 3H).

[0303] tert-Butyl 3-(4-((3-((3-methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (3)

[0304]

[0305] Using the procedure described for Compound 2, tert-butyl 3-(4-(((4S,7S)-4-(hydroxymethyl)-10,10,11,11-tetramethyl-3,6-dioxo-2,9-dioxa-5-aza-10-silaundecan-7-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate (0.728 g, 1.18 mmole) was converted to tert-butyl 3-(4-((3-((3-methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)piperidine-1-carboxylate as a white solid (0.126 g, 23%).

[0306] 1 H NMR (400 MHz, chloroform-d) δ 9.89 (s, 1H), 8.53 (s, 1H), 8.06 (s, 1H), 6.74 (d, J = 2.2 Hz, 1H), 6.69 (s, 1H), 6.01 (d, J = 1.2 Hz, 1H), 5.47 (t, J = 1.9 Hz, 1H), 4.39–4.26 (m, 1H), 4.09–3.94 (m, 1H), 3.90 (s, 3H), 3.25–3.03 (m, 2H), 3.01–2.86 (m, 1H), 2.31–2.16 (m, 1H), 1.90–1.73 (m, 2H), 1.64 (s, 1H), 1.48 (s, 9H).

[0307] Compound 4: 2-(2-(2-(4-(6-Bromohexanamido)phenyl)thiazole-4-carboxamido)acrylamido)acryloyl methyl ester

[0308] 6-Bromo-N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)hexanamide (4.1)

[0309]

[0310] 6-Bromohexanoic acid (1.964 g, 10.1 mmol) was dissolved in DCM (20 mL), and DMF (1 drop) was added. Oxalyl chloride (0.880 mL, 10.1 mmol) was added dropwise, and the solution was stirred at room temperature for 90 minutes and then concentrated. The residue was dissolved in DCM (2 mL) and added dropwise to a cold (0 °C) solution of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (2.007 g, 9.16 mmol) and N,N-diisopropylethylamine (3.20 mL, 18.4 mmol) in DCM (20 mL). The resulting solution was stirred at 0 °C for 60 minutes and then at room temperature for 2 hours. Water (50 mL) was added and the two layers were separated. The mixture was extracted with DCM (2 x 20 mL). The combined organic matter was dried over sodium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography (Isco CombiPrep, 24 g RediSep column, 10-30% ethyl acetate / hexane gradient) to afford 6-bromo-N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)hexanamide (3.241 g, 89%) as an orange solid.

[0311] 1H NMR (400 MHz, chloroform-d) δ 7.81–7.72 (m, 2H), 7.52 (d, J = 8.1 Hz, 2H), 7.17 (s, 1H), 3.42 (t, J = 6.7 Hz, 2H), 2.38 (t, J = 7.4 Hz, 2H), 1.96–1.85 (m, 2H), 1.79 (d, J = 7.5 Hz, 2H), 1.57–1.48 (m, 2H), 1.34 (s, 12H).

[0312] N-(2-(4-(6-Bromohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (4.2)

[0313]

[0314] N-(2-bromothiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (2.006 g, 4.74 mmol) was dissolved in 1,4-dioxane (9 mL). 6-Bromo-N-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)hexanamide (1.880 g, 4.75 mmol) was added followed by potassium carbonate (2 M aqueous solution, 4.70 mL, 9.40 mmol) and bis(triphenylphosphine)palladium(II) chloride (0.332 g, 0.473 mmol). The mixture was heated to 85 °C for 18 h and cooled to room temperature. Water (50 mL) was added and the mixture was extracted with ethyl acetate (3 x 20 mL). The combined organics were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography (Isco CombiPrep, 24 g RediSep column, 20-50% ethyl acetate / hexane gradient) to afford N-(2-(4-(6-bromohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (1.290 g, 44%) as a thick orange gel.

[0315] 1 H NMR (400 MHz, chloroform-d) δ 8.22 (d, J = 8.7 Hz, 1H), 8.05 (s, 1H), 7.94–7.85 (m, 2H), 7.67–7.60 (m, 2H), 7.51 (s, 1H), 4.90–4.81 (m, 1H), 4.22 (dd, J = 10.1, 2.6 Hz, 1H), 3.95 (dd, J = 10.0, 3.4 Hz, 1H), 3.79 (s, 3H), 3.43 (t, J = 6.7 Hz, 2H), 2.41 (t, J = 7.4 Hz, 2H), 1.92 (dq, J = 8.1, 6.8 Hz, 2H), 1.84–1.72 (m, 2H), 1.59–1.50 (m, 2H), 0.92 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[0316] N-(2-(4-(6-bromohexanamido)phenyl)thiazol)-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (4.3)

[0317]

[0318] Dissolve N-(2-(4-(6-bromohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (1.290 g, 2.11 mmole) in 4 / 1 / 1 THF / methanol / water (12 mL). Add lithium hydroxide (0.158 g, 6.60 mmole) and stir the mixture at room temperature for 2 h. Pour the mixture into water (40 mL) and treat the solution with 1 N hydrochloric acid to pH = 4. The slurry is extracted with ethyl acetate (3 x 15 mL). The combined organics are dried over sodium sulfate, filtered and concentrated to afford N-(2-(4-(6-bromohexanamido)phenyl)thiazol)-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine as an orange foam (1.213 g, 96%).

[0319] 1 H NMR (400 MHz, chloroform-d) δ 8.26 (d, J = 8.7 Hz, 1H), 8.05 (s, 1H), 7.84–7.81 (m, 2H), 7.74 (s, 1H), 7.67–7.60 (m, 2H), 4.90–4.81 (m, 1H), 4.26 (dd, J = 10.1, 2.6 Hz, 1H), 3.95 (dd, J = 10.0, 3.4 Hz, 1H), 3.43 (t, J = 6.7 Hz, 2H), 2.41 (t, J = 7.4 Hz, 2H), 1.92 (dq, J = 8.1, 6.8 Hz, 2H), 1.84–1.72 (m, 2H), 1.55–1.48 (m, 2H), 0.92 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[0320] N-(2-(4-(6-bromohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (4.4)

[0321]

[0322] Using the procedure described for Example 1.4, convert N-(2-(4-(6-bromohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (1.213 g, 2.03 mmole) into N-(2-(4-(6-bromohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester as a yellow gel (1.152 g, 81%).

[0323] 11H NMR (400 MHz, chloroform-d) δ 8.24 (d, J = 7.0 Hz, 1H), 8.06 (s, 1H), 7.90–7.84 (m, 2H), 7.65–7.60 (m, 2H), 7.49–7.45 (m, 1H), 7.42 (s, 1H), 4.69 (dq, J = 7.6, 3.8 Hz, 1H), 4.64 (dt, J = 6.7, 3.3 Hz, 1H), 4.25–4.16 (m, 1H), 4.05–3.93 (m, 2H), 3.89–3.81 (m, 1H), 3.79 (s, 3H), 3.44 (t, J = 6.7 Hz, 2H), 2.43 (t, J = 7.4 Hz, 2H), 1.84–1.73 (m, 3H), 1.57 (q, J = 8.3 Hz, 3H), 0.95 (s, 9H), 0.14 (s, 3H), 0.14 (s, 3H).

[0324] Methyl 2-(2-(2-(4-(6-bromohexanamido)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (4)

[0325]

[0326] Using the procedure described for compound 2, N-(2-(4-(6-bromohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (1.151 g, 1.64 mmol) was converted to methyl 2-(2-(2-(4-(6-bromohexanamido)phenyl)thiazole-4-carboxamido)acrylamide)acrylate (0.275 g, 31%) as a white solid.

[0327] 1 1H NMR (400 MHz, chloroform-d) δ 10.00 (s, 1H), 8.55 (s, 1H), 8.11 (s, 1H), 8.04–7.90 (m, 2H), 7.64 (d, J = 8.3 Hz, 2H), 6.78 (d, J = 2.2 Hz, 1H), 6.74–6.65 (m, 1H), 6.03 (d, J = 1.2 Hz, 1H), 5.50 (t, J = 1.9 Hz, 1H), 3.91 (s, 3H), 3.44 (t, J = 6.7 Hz, 2H), 2.43 (t, J = 7.4 Hz, 2H), 1.93 (dq, J = 9.1, 6.8 Hz, 2H), 1.80 (p, J = 7.6 Hz, 2H), 1.63–1.50 (m, 2H).

[0328] Compound 5: 2-(2-(2-(4-((tert-Butoxycarbonyl)amino)phenyl)thiazole-4-carboxamido)acrylamido) methyl acrylate

[0329] Ethyl 2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carboxylate (5.1)

[0330]

[0331] Dissolve ethyl 2-bromothiazole-4-carboxylate (1.006 g, 4.26 mmol) in 1,4-dioxane (8.5 mL). Add tert-butyl (4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)carbamate (1.491 g, 4.67 mmol) then add potassium carbonate (2 M aqueous solution, 4.20 mL, 8.40 mmol) and bis(triphenylphosphine)palladium(II) chloride (0.149 g, 0.212 mmol). Heat the mixture at 90 °C for 20 h and cool to room temperature. Add water (50 mL), and extract the mixture with ethyl acetate (3 x 15 mL). Dry the combined organics over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography (Isco CombiPrep, 24 g RediSep column, 10 - 25% ethyl acetate / hexane gradient) to afford ethyl 2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carboxylate (0.557 g, 38%) as a white solid.

[0332] 1 H NMR (400 MHz, chloroform-d) δ 8.10 (s, 1H), 7.99–7.90 (m, 2H), 7.50–7.41 (m, 2H), 6.62 (s, 1H), 4.44 (q, J = 7.1 Hz, 2H), 1.53 (s, 9H), 1.43 (t, J = 7.1 Hz, 3H).

[0333] 2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carboxylic acid (5.2)

[0334]

[0335] Using the procedure described for Example 1.3, convert ethyl 2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carboxylate (0.557 g, 1.60 mmol) to 2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carboxylic acid (0.442 g, 86%) as a white solid.

[0336] 1 H NMR (400 MHz, DMSO-d6) δ 13.06 (s, 1H), 9.69 (s, 1H), 8.41 (s, 1H), 7.94–7.78 (m, 2H), 7.67–7.54 (m, 2H), 1.50 (s, 9H).

[0337] 2,5-Dioxopyrrolidin-1-yl 2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carboxylate (5.3)

[0338]

[0339] Dissolve 2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carboxylic acid (0.442 g, 1.38 mmol) in DMF (5 mL). Add N-hydroxysuccinimide (0.194 g, 1.69 mmol) and then add EDC·HCl (0.533 g, 2.78 mmol), and stir the mixture at room temperature for 90 minutes. Add water (50 mL), and extract the mixture with ethyl acetate (3 x 15 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography (Isco CombiPrep, 12 g RediSep column, 30 - 50% ethyl acetate / hexane gradient) to afford 2,5-dioxopyrrolidin-1-yl 2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carboxylate as a white solid (0.376 g, 65%).

[0340] 1 H NMR (400 MHz, chloroform-d) δ 8.38 (s, 1H), 7.97–7.87 (m, 2H), 7.53–7.42 (m, 2H), 6.69 (s, 1H), 2.92 (s, 4H), 1.53 (s, 9H).

[0341] (2-(4-((tert-butoxycarbonyl)amino)phenyl)-thiazole-4-carbonyl)-L-serine methyl ester (5.4)

[0342]

[0343] 2,5-Dioxopyrrolidin-1-yl 2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carboxylate (0.376 g, 0.901 mmol) was suspended in DCM (4 mL). L-Serine methyl ester hydrochloride (0.168 g, 1.08 mmol) was added followed by N,N-diisopropylethylamine (0.320 mL, 1.84 mmol). The mixture was stirred at room temperature for 20 h and water (25 mL) was added. The mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over sodium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography (Isco CombiPrep, 12 g RediSep column, 40-70% ethyl acetate / hexane gradient) to afford (2-(4-((tert-butoxycarbonyl)amino)phenyl)-thiazole-4-carbonyl)-L-serine methyl ester (0.355 g, 93%) as a white solid.

[0344] 1 H NMR (400 MHz, chloroform-d) δ 8.24 (d, J = 7.5 Hz, 1H), 8.06 (s, 1H), 7.94–7.85 (m, 2H), 7.51–7.43 (m, 2H), 6.64 (s, 1H), 4.88 (dt, J = 7.6, 3.8 Hz, 1H), 4.17–4.05 (m, 2H), 3.85 (s, 3H), 2.63 (t, J = 6.2 Hz, 1H), 1.54 (s, 9H).

[0345] N-(2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (5.5)

[0346]

[0347] Using the general procedure described for Examples 4.2 and 4.3, (2-(4-((tert-butoxycarbonyl)amino)phenyl)-thiazole-4-carbonyl)-L-serine methyl ester (0.355 g, 0.842 mmol) was converted to N-(2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (0.297 g, 68%) as a white solid.

[0348] 11H NMR (400 MHz, chloroform-d) δ 8.25 (d, J = 7.7 Hz, 1H), 8.08 (s, 1H), 7.94–7.86 (m, 2H), 7.45 (d, J = 8.4 Hz, 2H), 4.84 (dt, J = 8.0, 4.1 Hz, 1H), 4.27 (dd, J = 10.1, 3.4 Hz, 1H), 3.98 (dd, J = 10.0, 4.4 Hz, 1H), 1.56 (s, 9H), 0.92 (s, 9H), 0.08 (s, 6H).

[0349] N-(2-(4-((tert-Butoxycarbonyl)amino)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (5.6)

[0350]

[0351] Using the procedure described for Example 1.4 and using pyBOP as the coupling reagent, N-(2-(4-((tert-Butoxycarbonyl)amino)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (0.297 g, 0.569 mmol) was converted to N-(2-(4-((tert-Butoxycarbonyl)amino)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (0.385 g) as a colorless solid.

[0352] 1 1H NMR (400 MHz, chloroform-d) δ 8.25 (d, J = 7.0 Hz, 1H), 8.06 (d, J = 4.9 Hz, 1H), 7.91–7.82 (m, 2H), 7.50–7.39 (m, 3H), 6.66 (s, 1H), 4.69 (dt, J = 7.1, 3.6 Hz, 1H), 4.64 (dq, J = 10.6, 4.0, 3.3 Hz, 1H), 4.21 (ddd, J = 9.8, 3.9, 1.0 Hz, 1H), 3.99 (dd, J = 3.7, 1.0 Hz, 2H), 3.84 (dd, J = 9.8, 6.6 Hz, 1H), 3.78 (s, 3H), 1.54 (s, 9H), 0.94 (s, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[0353] Methyl 2-(2-(2-(4-((tert-Butoxycarbonyl)amino)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (5)

[0354]

[0355] Using the procedure described for Compound 5, N-(2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (0.385 g, 0.618 mmol) was converted to methyl 2-(2-(2-(4-((tert-butoxycarbonyl)amino)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (0.033 g, 12%).

[0356] 1 H NMR (400 MHz, DMSO-d6) δ 9.97 (s, 1H), 9.93 (s, 1H), 9.72 (s, 1H), 8.40 (s, 1H), 7.96–7.84 (m, 2H), 7.69–7.58 (m, 2H), 6.51 (d, J = 1.3 Hz, 1H), 5.87 (s, 2H), 5.84 (s, 1H), 3.75 (s, 3H), 1.49 (s, 9H).

[0357] Compound 6: 2-(2-(2-(6-((6-((Methylsulfonyl)oxy)hexyl)carbamoyl)pyridin-3-yl)thia zole-4-carboxamido)acrylamido)methyl acrylate

[0358] 5-Bromo-N-(6-hydroxyhexyl)picolinamide (6.1)

[0359]

[0360] 5-Bromopicolinic acid (1.006 g, 4.98 mmol) was suspended in DCM (10 mL), and N,N'-carbonyldiimidazole (0.887 g, 5.47 mmol) was added (gas evolution was observed). The mixture was stirred at room temperature for 90 minutes, and 6-aminohexan-1-ol (0.706 g, 6.02 mmol) was added. The resulting solution was stirred at room temperature for 3 hours, then water (50 mL) was added. The two layers were separated, and the aqueous layer was extracted with DCM (2 x 15 mL). The combined organics were dried over sodium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography to afford 5-bromo-N-(6-hydroxyhexyl)picolinamide (1.019 g, 68%) as a white solid.

[0361] 1 H NMR (400 MHz, chloroform-d) δ 8.60 (dd, J = 2.2, 0.8 Hz, 1H), 8.09 (dd, J = 8.3, 0.7 Hz, 1H), 7.98 (dd, J = 8.4, 2.3 Hz, 1H), 7.93 (s, 1H), 3.64 (t, J = 6.5 Hz, 2H), 3.47 (td, J = 7.1, 6.2 Hz, 2H), 1.76–1.55 (m, 4H), 1.43 (p, J = 3.6 Hz, 4H).

[0362] 5-Bromo-N-(6-((tert-butyldimethylsilyl)oxy)hexyl)picolinamide (6.2)

[0363]

[0364] 5-Bromo-N-(6-hydroxyhexyl)picolinamide (1.019 g, 3.38 mmol) was dissolved in DMF (7 mL). Imidazole (0.258 g, 3.79 mmol) was added and then tert-butyldimethylchlorosilane (0.571 g, 3.79 mmol) was added. The solution was stirred at room temperature for 2 h and poured into water (50 mL). The mixture was extracted with ethyl acetate (3 x 15 mL). The combined organics were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford 5-bromo-N-(6-((tert-butyldimethylsilyl)oxy)hexyl)picolinamide (1.260 g, 90%) as a colorless oil.

[0365] 1 H NMR (400 MHz, chloroform-d) δ 8.59 (dd, J = 2.3, 0.8 Hz, 1H), 8.09 (dd, J = 8.3, 0.7 Hz, 1H), 7.97 (dd, J = 8.3, 2.3 Hz, 1H), 7.91 (s, 1H), 3.60 (t, J = 6.5 Hz, 2H), 3.45 (td, J = 7.2, 6.1 Hz, 2H), 1.64 (dd, J = 8.5, 6.0 Hz, 2H), 1.53 (p, J = 6.6 Hz, 2H), 1.45–1.34 (m, 4H), 0.89 (s, 9H), 0.04 (s, 6H).

[0366] N-(6-((tert-butyldimethylsilyl)oxy)hexyl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)picolinamide (6.3)

[0367]

[0368] 5-Bromo-N-(6-((tert-butyldimethylsilyl)oxy)hexyl)picolinamide (1.260 g, 3.03 mmole) was dissolved in 1,4-dioxane (18 mL) and placed under a nitrogen atmosphere. Bis(pinacolato)diboron (1.165 g, 4.59 mmole) was added followed by potassium acetate (0.745 g, 7.59 mmole) and 1,1'-bis(diphenylphosphino)ferrocene palladium(II) dichloride (0.221 g, 0.302 mmole). The mixture was heated to 85 °C for 18 h and cooled to room temperature. Water (75 mL) was added and the mixture was extracted with ethyl acetate (3 x 25 mL). The combined organics were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford N-(6-((tert-butyldimethylsilyl)oxy)hexyl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)picolinamide (1.952 g) as a brown oil.

[0369] 1 H NMR (400 MHz, chloroform-d) δ 8.85 (dd, J = 1.6, 1.0 Hz, 1H), 8.21 (dd, J = 7.7, 1.7 Hz, 1H), 8.17 (dd, J = 7.8, 1.0 Hz, 1H), 8.12 (d, J = 6.2 Hz, 1H), 3.60 (t, J = 6.5 Hz, 2H), 3.47 (td, J = 7.2, 6.1 Hz, 2H), 1.65 (h, J = 6.8 Hz, 2H), 1.53 (p, J = 6.6 Hz, 2H), 1.36 (s, 16H), 0.89 (s, 9H), 0.04 (s, 6H).

[0370] O-(tert-Butyldimethylsilyl)-N-(2-(6-((5-(tert-butyldimethylsilyl)oxy)pentyl)carbamoyl)pyridin-3-yl)thiazole-4-carbonyl)-L-serine methyl ester (6.4)

[0371]

[0372] N-(2-bromothiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (0.759 g, 1.79 mmol) was dissolved in 1,4-dioxane (3.6 mL), and N-(6-((tert-butyldimethylsilyl)oxy)hexyl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)picolinamide (1.073 g, 2.32 mmol) was added. Potassium carbonate (2 M aqueous solution, 1.80 mL, 3.60 mmol) and bis(triphenylphosphine)palladium(II) chloride (0.132 g, 0.188 mmol) were added, and the mixture was heated to 85 °C for 3 h. The mixture was cooled to room temperature and poured into water (50 mL), and extracted with ethyl acetate (3 x 15 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford O-(tert-butyldimethylsilyl)-N-(2-(6-((5-(tert-butyldimethylsilyl)oxy)pentyl)carbamoyl)pyridin-3-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.733 g, 62%) as an orange oil.

[0373] 1 H NMR (400 MHz, chloroform-d) δ 9.10 (dd, J = 2.2, 0.9 Hz, 1H), 8.40 (dd, J = 8.2, 2.2 Hz, 1H), 8.30 (dd, J = 8.2, 0.9 Hz, 1H), 8.23 (s, 1H), 8.19 (d, J = 8.8 Hz, 1H), 8.04 (t, J = 6.0 Hz, 1H), 4.87 (dt, J = 8.7, 3.0 Hz, 1H), 4.22 (dd, J = 10.1, 2.6 Hz, 1H), 3.96 (dd, J = 10.1, 3.4 Hz, 1H), 3.80 (s, 3H), 3.61 (t, J = 6.5 Hz, 2H), 3.50 (td, J = 7.2, 6.1 Hz, 2H), 1.68 (p, J = 7.4 Hz, 2H), 1.54 (q, J = 6.7 Hz, 2H), 1.42 (dt, J = 8.7, 5.5 Hz, 4H), 0.92 (s, 9H), 0.89 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H), 0.05 (s, 6H).

[0374] O-(tert-butyldimethylsilyl)-N-(2-(6-((5-((tert-butyldimethylsilyl)oxy)pentyl)carbamoyl)pyridin-3-yl)thiazole-4-carbonyl)-L-serine (6.5)

[0375]

[0376] Dissolve O-(tert-butyldimethylsilyl)-N-(2-(6-((5-(tert-butyldimethylsilyloxy)pentyl)carbamoyl)pyridin-3-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.733 g, 1.10 mmol) in 4 / 1 / 1 THF / methanol / water (6 mL). Add lithium hydroxide (0.080 g, 3.34 mmol), and stir the mixture at room temperature for 3 hours. Pour the mixture into water (25 mL), and treat with 1 N hydrochloric acid to pH = 4. Extract the slurry with ethyl acetate (3 x 10 mL). Dry the combined organic layers over sodium sulfate, filter, and concentrate to afford O-(tert-butyldimethylsilyl)-N-(2-(6-((5-((tert-butyldimethylsilyloxy)pentyl)carbamoyl)pyridin-3-yl)thiazole-4-carbonyl)-L-serine (0.677 g, 95%) as an orange solid.

[0377] 1H NMR (400 MHz, chloroform-d) δ 9.08 (dd, J = 2.2, 0.8 Hz, 1H), 8.47–8.40 (m, 1H), 8.36 (dt, J = 8.2, 1.1 Hz, 1H), 8.28 (d, J = 8.8 Hz, 1H), 8.23 (d, J = 8.1 Hz, 1H), 8.09 (t, J = 6.1 Hz, 1H), 4.88 (ddd, J = 8.1, 4.1, 3.0 Hz, 1H), 4.33–4.24 (m, 1H), 3.99 (dd, J = 10.2, 4.0 Hz, 1H), 3.62 (t, J = 6.4 Hz, 2H), 3.51 (q, J = 7.0 Hz, 2H), 1.67 (q, J = 7.6, 7.2 Hz, 2H), 1.59–1.50 (m, 2H), 1.42 (tq, J = 9.5, 5.3, 4.2 Hz, 4H), 0.94–0.91 (m, 9H), 0.89 (s, 9H), 0.09 (s, 6H), 0.05 (s, 6H).

[0378] O-(tert-butyldimethylsilyl)-N-(2-(6-((5-((tert-butyldimethylsilyloxy)pentyl)carbamoyl)pyridin-3-yl)thiazole-4-carbonyl)-L-seryl-L-serine methyl ester (6.6)

[0379]

[0380] Using the procedure described for Example 1.4 and using pyBOP as the coupling reagent, O-(tert-butyldimethylsilyl)-N-(2-(6-((5-((tert-butyldimethylsilyl)oxy)pentyl)carbamoyl)pyridin-3-yl)thiazole-4-carbonyl)-L-serine (0.677 g, 1.04 mmole) was converted to O-(tert-butyldimethylsilyl)-N-(2-(6-((5-((tert-butyldimethylsilyl)oxy)pentyl)carbamoyl)pyridin-3-yl)thiazole-4-carbonyl)-L-seryl-L-serine methyl ester as a pale yellow oil (0.534 g, 68%).

[0381] 1H NMR (400 MHz, chloroform-d) δ 9.09 (ddd, J = 4.3, 2.2, 0.9 Hz, 1H), 8.39 (ddd, J = 8.2, 4.8, 2.2 Hz, 1H), 8.33–8.26 (m, 1H), 8.24 (d, J = 3.8 Hz, 2H), 8.04 (t, J = 6.0 Hz, 1H), 7.47 (d, J = 7.1 Hz, 1H), 4.75–4.61 (m, 2H), 4.22 (dt, J = 9.8, 3.8 Hz, 1H), 4.04–3.96 (m, 2H), 3.86 (dt, J = 9.9, 6.5 Hz, 1H), 3.79 (s, 3H), 3.61 (t, J = 6.5 Hz, 2H), 3.50 (q, J = 6.8 Hz, 2H), 1.69 (q, J = 7.2 Hz, 2H), 1.54 (p, J = 6.7 Hz, 2H), 1.41 (dd, J = 7.4, 4.3 Hz, 4H), 0.95 (s, 9H), 0.89 (s, 9H), 0.16 (s, 3H), 0.14 (s, 3H), 0.05 (s, 6H).

[0382] Methyl 2-(2-(2-(6-((6-((methylsulfonyl)oxy)hexyl)carbamoyl)pyridin-3-yl)thiazole-4-carboxamido)acrylamide (6)

[0383]

[0384] Using the procedure described for Compound 2, O-(tert-butyldimethylsilyl)-N-(2-(6-((5-((tert-butyldimethylsilyl)oxy)pentyl)carbamoyl)pyridin-3-yl)thiazole-4-carbonyl)-L-seryl-L-serine methyl ester (0.534 g, 0.710 mmole) was converted to methyl 2-(2-(2-(6-((6-((methylsulfonyl)oxy)hexyl)carbamoyl)pyridin-3-yl)thiazole-4-carboxamido)acrylamide)acrylate as a white solid (0.073 g, 18%).

[0385] 1 H NMR (400 MHz, chloroform-d) δ 10.02 (s, 1H), 9.19 (dd, J = 2.2, 0.8 Hz, 1H), 8.57 (s, 1H), 8.44 (dd, J = 8.1, 2.2 Hz, 1H), 8.31 (dd, J = 8.1, 0.8 Hz, 1H), 8.27 (s, 1H), 8.06 (t, J = 6.1 Hz, 1H), 6.80 (d, J = 2.3 Hz, 1H), 6.75–6.66 (m, 1H), 6.09–5.98 (m, 1H), 5.53 (t, J = 2.0 Hz, 1H), 4.24 (t, J = 6.5 Hz, 2H), 3.91 (s, 3H), 3.52 (q, J = 6.8 Hz, 2H), 3.01 (s, 3H), 1.79 (t, J = 7.0 Hz, 2H), 1.69 (p, J = 7.1 Hz, 2H), 1.52–1.43 (m, 4H).

[0386] Compound 7: 2-(2-(2-(4-Methoxyphenyl)thiazole-4-carboxamido)acrylamido)methyl acrylate

[0387] Ethyl 2-(4-methoxyphenyl)thiazole-4-carboxylate (7.1)

[0388]

[0389] Ethyl 2-bromothiazole-4-carboxylate (0.500 g, 2.12 mmol) was dissolved in 1,4-dioxane (4 mL). 2-(4-Methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.593 g, 2.53 mmol) was added followed by potassium carbonate (2 M aqueous solution, 2.10 mL, 4.20 mmol) and bis(triphenylphosphine)palladium(II) chloride (0.147 g, 0.209 mmol). The mixture was heated to 80 °C for 5 h and cooled to room temperature. Water (25 mL) was added and the mixture was extracted with ethyl acetate (3 x 10 mL). The combined organics were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography (Isco CombiPrep, 12 g Silicycle column, 10 - 30% ethyl acetate / hexane gradient) to afford ethyl 2-(4-methoxyphenyl)thiazole-4-carboxylate (0.249 g, 45%) as a white solid.

[0390] 1 H NMR (400 MHz, chloroform-d) δ 8.09 (s, 1H), 7.99–7.90 (m, 2H), 7.00–6.90 (m, 2H), 4.44 (q, J = 7.1 Hz, 2H), 3.87 (s, 3H), 1.43 (t, J = 7.1 Hz, 3H).

[0391] 2-(4-Methoxyphenyl)thiazole-4-carboxylic acid (7.2)

[0392]

[0393] Using the procedure described for Example 4.3, ethyl 2-(4-methoxyphenyl)thiazole-4-carboxylate (0.249 g, 0.946 mmol) was converted to 2-(4-methoxyphenyl)thiazole-4-carboxylic acid (0.248 g, 100%) as a cream solid.

[0394] 1 H NMR (400 MHz, DMSO-d6) δ 13.05 (s, 1H), 8.41 (s, 1H), 7.98–7.85 (m, 2H), 7.15–7.01 (m, 2H), 3.84 (s, 3H).

[0395] (2-(4-Methoxyphenyl)thiazole-4-carbonyl)-L-serine methyl ester (7.3)

[0396]

[0397] Using the procedure described for Example 1.4, 2-(4-methoxyphenyl)thiazole-4-carboxylic acid (0.248 g, 1.05 mmole) was converted into (2-(4-methoxyphenyl)thiazole-4-carbonyl)-L-serine methyl ester as a white solid (0.292 g, 83%).

[0398] 1 H NMR (400 MHz, chloroform-d) δ 8.26 (d, J = 7.5 Hz, 1H), 8.05 (s, 1H), 7.96–7.86 (m, 2H), 7.02–6.92 (m, 2H), 4.88 (dt, J = 7.6, 3.8 Hz, 1H), 4.17–4.05 (m, 2H), 3.88 (s, 3H), 3.85 (s, 3H).

[0399] O-(tert-Butyldimethylsilyl)-N-(2-(4-methoxyphenyl)thiazole-4-carbonyl)-L-serine (7.4)

[0400]

[0401] Using the procedures described for Examples 4.2 and 4.3, (2-(4-methoxyphenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.292 g, 0.868 mmole) was converted into O-(tert-butyldimethylsilyl)-N-(2-(4-methoxyphenyl)thiazole-4-carbonyl)-L-serine (0.269 g), which was a mixture of products for continued use without additional purification.

[0402] O-(tert-Butyldimethylsilyl)-N-(2-(4-methoxyphenyl)thiazole-4-carbonyl)-L-seryl-L-serine methyl ester (7.5)

[0403]

[0404] Using the procedure described for Example 1.4, O-(tert-butyldimethylsilyl)-N-(2-(4-methoxyphenyl)thiazole-4-carbonyl)-L-serine (0.269 g) was converted into O-(tert-butyldimethylsilyl)-N-(2-(4-methoxyphenyl)thiazole-4-carbonyl)-L-seryl-L-serine methyl ester as a white solid (0.097 g, 29%). 11H NMR (400 MHz, CDCl3) δ 8.26 (d, J = 7.0 Hz, 1H), 8.03 (s, 1H), 7.93–7.83 (m, 2H), 7.46 (d, J = 7.1 Hz, 1H), 6.99–6.90 (m, 2H), 4.70 (dd, J = 7.2, 3.7 Hz, 1H), 4.65 (td, J = 6.9, 4.2 Hz, 1H), 4.21 (dd, J = 9.8, 4.1 Hz, 1H), 3.99 (dd, J = 3.7, 1.0 Hz, 2H), 3.88 (s, 3H), 3.84 (dd, J = 9.8, 6.7 Hz, 1H), 3.79 (s, 3H), 0.95 (s, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[0405] Methyl 2-(2-(2-(4-methoxyphenyl)thiazole-4-carboxamido)acrylamido)acrylate (7)

[0406]

[0407] Using the procedure described for compound 2, O-(tert-butyldimethylsilyl)-N-(2-(4-methoxyphenyl)thiazole-4-carbonyl)-L-seryl-L-serine methyl ester (0.097 g, 0.180 mmol) was converted to methyl 2-(2-(2-(4-methoxyphenyl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.0203 g, 29%).

[0408] 1 1H NMR (400 MHz, CDCl3) δ 10.02 (s, 1H), 8.55 (s, 1H), 8.07 (s, 1H), 8.00–7.92 (m, 2H), 7.02–6.92 (m, 2H), 6.78 (d, J = 2.2 Hz, 1H), 6.71 (s, 1H), 6.03 (d, J = 1.3 Hz, 1H), 5.49 (t, J = 1.9 Hz, 1H), 3.90 (s, 3H), 3.88 (s, 3H).

[0409] Compound 8: 2-(2-(2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carboxamido)acry lamido)methyl acrylate

[0410] tert-Butyl (4-bromobenzyl)carbamate (8.1)

[0411]

[0412] 4-Bromobenzylamine (2.006 g, 10.8 mmol) was dissolved in DCM (22 mL), and N,N-diisopropylethylamine (2.45 mL, 14.1 mmol) was added. Di-tert-butyl dicarbonate (2.600 g, 11.9 mmol) was added, and the solution was stirred at room temperature for 5 h. The mixture was concentrated and the crude residue was purified by silica gel chromatography (Isco CombiPrep, 40 g Silicycle column, 10-25% ethyl acetate / hexane gradient) to afford tert-butyl (4-bromobenzyl)carbamate (2.732 g, 88%) as a white solid.

[0413] 1 H NMR (400 MHz, chloroform-d) δ 7.48–7.39 (m, 2H), 7.20–7.11 (m, 2H), 4.84 (s, 1H), 4.26 (d, J = 6.1 Hz, 2H), 1.46 (s, 9H).

[0414] tert-Butyl (4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl)carbamate (8.2)

[0415]

[0416] tert-Butyl (4-bromobenzyl)carbamate (2.732 g, 9.55 mmol) was dissolved in 1,4-dioxane (19 mL). Bis(pinacolato)diboron (2.914 g, 11.5 mmol) was added followed by potassium acetate (2.032 g, 20.7 mmol) and 1,1'-bis(diphenylphosphino)ferrocene palladium(II) dichloride (0.697 g, 0.953 mmol). The mixture was heated to 80 °C for 5 h and cooled to room temperature. Water (50 mL) was added and the mixture was extracted with ethyl acetate (3 x 20 mL). The combined organics were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography (Isco CombiPrep, 40 g Silicycle column, 5-20% ethyl acetate / hexane gradient) to afford tert-butyl (4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl)carbamate (4.231 g) as a golden oil, which was carried on to the next step without further purification.

[0417] 1 H NMR (400 MHz, chloroform-d) δ 7.80–7.73 (m, 2H), 7.28 (d, J = 8.1 Hz, 2H), 4.89 (s, 1H), 4.32 (d, J = 6.0 Hz, 2H), 1.45 (s, 9H), 1.34 (s, 12H).

[0418] Ethyl 2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carboxylate (8.3)

[0419]

[0420] Dissolve ethyl 2-bromothiazole-4-carboxylate (0.504 g, 2.13 mmol) in 1,4-dioxane (4 mL). Add (4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl)carbamic acid tert-butyl ester (0.862 g, 2.59 mmol) and then add potassium carbonate (2 M aqueous solution, 2.10 mL, 4.20 mmol) and bis(triphenylphosphine)palladium(II) chloride (0.149 g, 0.212 mmol). Heat the mixture at 80 °C for 20 h. Cool the mixture to room temperature and add water (50 mL). Extract the mixture with ethyl acetate (3 x 15 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography (Isco CombiPrep, 12 g Silicycle column, 10-30% ethyl acetate / hexane gradient) to afford ethyl 2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carboxylate (0.400 g, 52%) as a yellow solid.

[0421] 1 H NMR (400 MHz, chloroform-d) δ 8.15 (s, 1H), 8.01–7.92 (m, 2H), 7.41–7.32 (m, 2H), 4.92 (s, 1H), 4.51–4.40 (m, 2H), 4.35 (dd, J = 9.9, 6.7 Hz, 2H), 1.51–1.45 (m, 9H), 1.45–1.40 (m, 3H).

[0422] 2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carboxylic acid (8.4)

[0423]

[0424] Using the procedure described for Example 4.3, convert ethyl 2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carboxylate (0.400 g, 1.10 mmol) to 2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carboxylic acid (0.338 g, 92%) as a white solid.

[0425] 11H NMR (400 MHz, DMSO-d6) δ 13.10 (s, 1H), 8.48 (s, 1H), 8.00–7.84 (m, 2H), 7.48 (t, J = 6.2 Hz, 1H), 7.38 (d, J = 8.2 Hz, 2H), 4.19 (d, J = 6.2 Hz, 2H), 1.40 (s, 9H).

[0426] (2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (8.5)

[0427]

[0428] Using the procedure described for Example 1.4, 2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carboxylic acid (0.338 g, 1.01 mmol) was converted to (2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.336 g, 76%) as a white solid.

[0429] 1 1H NMR (400 MHz, chloroform-d) δ 8.26 (d, J = 7.5 Hz, 1H), 8.11 (s, 1H), 7.92 (d, J = 8.1 Hz, 2H), 7.37 (d, J = 8.0 Hz, 2H), 4.95 (s, 1H), 4.88 (dt, J = 7.5, 3.8 Hz, 1H), 4.37 (d, J = 6.1 Hz, 2H), 4.17–4.05 (m, 2H), 3.85 (s, 3H), 1.48 (s, 9H).

[0430] N-(2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (8.6)

[0431]

[0432] Using the procedure described for Examples 4.2 and 4.3, (2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.336 g, 0.772 mmol) was converted to N-(2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (0.334 g, 81%) as a white solid.

[0433] 11H NMR (400 MHz, DMSO-d6) δ 8.41 (s, 1H), 8.23 (d, J = 8.6 Hz, 1H), 8.04–7.94 (m, 2H), 7.53 (t, J = 6.2 Hz, 1H), 7.43 (d, J = 8.0 Hz, 2H), 4.63 (dt, J = 8.6, 3.5 Hz, 1H), 4.24 (d, J = 6.2 Hz, 2H), 4.16 (dd, J = 10.3, 3.4 Hz, 1H), 3.99 (dd, J = 10.3, 3.7 Hz, 1H), 1.45 (s, 9H), 0.93 (s, 9H), 0.10 (s, 3H), 0.08 (s, 3H).

[0434] N-(2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (8.7)

[0435]

[0436] Using the procedure described for Example 1.4, N-(2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (0.334 g, 0.623 mmole) was converted to N-(2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester as a colorless gel (0.263 g, 66%).

[0437] 1 1H NMR (400 MHz, CDCl3) δ 8.26 (d, J = 7.0 Hz, 1H), 8.09 (s, 1H), 7.95–7.83 (m, 2H), 7.47 (d, J = 7.3 Hz, 1H), 7.35 (d, J = 8.2 Hz, 2H), 4.95 (s, 1H), 4.70 (dt, J = 7.3, 3.7 Hz, 1H), 4.66 (dt, J = 6.7, 3.3 Hz, 1H), 4.37 (d, J = 6.1 Hz, 2H), 4.21 (dd, J = 9.9, 4.1 Hz, 1H), 4.04–3.94 (m, 2H), 3.88–3.81 (m, 1H), 3.79 (s, 3H), 1.48 (s, 9H), 0.95 (s, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[0438] Methyl 2-(2-(2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (8)

[0439]

[0440] Using the procedure described for Compound 2, N-(2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (0.263 g, 0.413 mmol) was converted to methyl 2-(2-(2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.0461 g, 15%).

[0441] 1 H NMR (400 MHz, CDCl3) δ 10.02 (s, 1H), 8.55 (s, 1H), 8.14 (s, 1H), 8.03–7.93 (m, 2H), 7.38 (d, J = 8.2 Hz, 2H), 6.78 (d, J = 2.2 Hz, 1H), 6.71 (d, J = 0.5 Hz, 1H), 6.03 (d, J = 1.3 Hz, 1H), 5.50 (t, J = 1.9 Hz, 1H), 4.92 (s, 1H), 4.38 (d, J = 6.1 Hz, 2H), 3.91 (s, 3H), 1.48 (s, 9H).

[0442] Compound 9: 4-(4-((3-((3-Methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2- yl)carbamoyl)thiazol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylic acid tert-butyl ester

[0443] (S)-tert-butyl 4-(4-((3-((tert-butyldimethylsilyl)oxy)-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate (9.1)

[0444]

[0445] Dissolve N-(2-bromothiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (0.511 g, 1.21 mmol) in 1,4-dioxane (4 mL). Add tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate (0.440 g, 1.42 mmol), then add potassium carbonate (2 M aqueous solution, 1.20 mL, 2.40 mmol) and bis(triphenylphosphine)palladium(II) chloride (0.086 g, 0.123 mmol). Heat the mixture at 80 °C for 18 h. Cool the mixture to room temperature and pour it into water (25 mL), then extract with ethyl acetate (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford tert-butyl (S)-4-(4-((3-((tert-butyldimethylsilyl)oxy)-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate (0.556 g, 87%).

[0446] 1 H NMR (400 MHz, CDCl3) δ 8.09 (t, J = 8.6 Hz, 1H), 7.99 (s, 1H), 6.57 (s, 1H), 4.82 (ddd, J = 8.7, 3.3, 2.6 Hz, 1H), 4.18 (dd, J = 10.0, 2.6 Hz, 1H), 4.13 (dd, J = 8.5, 5.8 Hz, 3H), 3.92 (dd, J = 10.1, 3.3 Hz, 1H), 3.77 (s, 3H), 3.72–3.54 (m, 2H), 2.70 (s, 2H), 1.50 (s, 9H), 0.89 (s, 9H), 0.05 (s, 3H).

[0447] N-(2-(1-(tert-Butoxycarbonyl)-1,2,3,6-tetrahydropyridin-4-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (9.2)

[0448]

[0449] (S)-4-(4-((3-((tert-Butyldimethylsilyl)oxy)-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylic acid tert-butyl ester (0.556 g, 1.06 mmol) was dissolved in 4 / 1 / 1 THF / methanol / water (6 mL). Lithium hydroxide (0.086 g, 3.59 mmol) was added and the mixture was stirred at room temperature for 2 h. Water (25 mL) was added and the solution was treated with 1 N hydrochloric acid to pH = 4. The slurry was extracted with ethyl acetate (3 x 10 mL). The combined organics were dried over sodium sulfate, filtered and concentrated to afford N-(2-(1-(tert-butoxycarbonyl)-1,2,3,6-tetrahydropyridin-4-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine as an orange gel (0.501 g, 92%).

[0450] 1 H NMR (400 MHz, DMSO) δ 8.31 (s, 1H), 8.06 (d, J = 8.7 Hz, 1H), 6.75 (d, J = 14.0 Hz, 1H), 4.59 (dt, J = 8.6, 3.4 Hz, 1H), 4.15–4.10 (m, 3H), 3.95 (dd, J = 10.3, 3.5 Hz, 2H), 3.64–3.54 (m, 2H), 2.64 (s, 2H), 1.47 (s, 9H), 0.90 (d, J = 3.7 Hz, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[0451] 4-(4-((((4S,7S)-4-(Hydroxymethyl)-10,10,11,11-tetramethyl-3,6-dioxo-2,9-dioxa-5-azasilaundecan-7-yl)carbamoyl)thiazol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylic acid tert-butyl ester (9.3)

[0452]

[0453] Using the procedure for Example 2.7, N-(2-(1-(tert-butoxycarbonyl)-1,2,3,6-tetrahydropyridin-4-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (0.501 g, 0.979 mmol) was converted to 4-(4-((((4S,7S)-4-(hydroxymethyl)-10,10,11,11-tetramethyl-3,6-dioxo-2,9-dioxa-5-azasilaundecan-7-yl)carbamoyl)thiazol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylic acid tert-butyl ester as a white solid (0.264 g, 44%).

[0454] 1 1H NMR (400 MHz, CDCl3) δ 8.01 (d, J = 5.3 Hz, 1H), 7.46 (dd, J = 13.4, 7.1 Hz, 1H), 6.57 (d, J = 3.6 Hz, 1H), 4.68 (dt, J = 6.9, 3.4 Hz, 1H), 4.66–4.55 (m, 1H), 4.22–4.09 (m, 2H), 3.98 (d, J = 3.6 Hz, 2H), 3.82 (dt, J = 10.5, 3.5 Hz, 1H), 3.80–3.73 (m, 3H), 3.61 (q, J = 7.2, 6.7 Hz, 1H), 2.69 (s, 1H), 1.50 (d, J = 5.6 Hz, 9H), 0.92 (s, 9H), 0.12 (d, J = 3.6 Hz, 6H).

[0455] tert-Butyl 4-(4-((3-((3-methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate (9)

[0456]

[0457] Using the procedure for compound 2, tert-butyl 4-(4-(((4S,7S)-4-(hydroxymethyl)-10,10,11,11-tetramethyl-3,6-dioxo-2,9-dioxa-5-azadisiloxane-7-yl)carbamoyl)thiazol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate (0.264 g, 0.431 mmol) was converted to tert-butyl 4-(4-((3-((3-methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate as a white solid (0.052 g, 27%).

[0458] 1 1H NMR (400 MHz, CDCl3) δ 9.91 (s, 1H), 8.53 (s, 1H), 8.04 (s, 1H), 6.76 (d, J = 2.2 Hz, 1H), 6.69 (s, 1H), 6.66–6.60 (m, 1H), 6.02 (d, J = 1.3 Hz, 1H), 5.48 (t, J = 1.9 Hz, 1H), 4.20–4.11 (m, 2H), 3.90 (s, 3H), 3.65 (t, J = 5.7 Hz, 2H), 2.74 (qd, J = 4.6, 4.1, 2.4 Hz, 2H), 1.49 (s, 9H).

[0459] Compound 10: 2-(2-(2-(4-((2-Methoxyethyl)carbamoyl)phenyl)thiazole-4-carboxamido)prop enamido)methyl acrylate

[0460] N-(2-Methoxyethyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzamide (10.1)

[0461]

[0462] Dissolve 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid (0.503 g, 2.03 mmol) in DCM (4 mL). Add 2-methoxyethylamine (0.210 mL, 2.42 mmol) then add N,N-diisopropylethylamine (0.700 mL, 4.02 mmol) and pyBOP (1.268 g, 2.44 mmol). Stir the mixture at room temperature for 6 h. Add water (25 mL) and extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over sodium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography to afford N-(2-methoxyethyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzamide (0.561 g, 91%) as a colorless oil.

[0463] 1 H NMR (400 MHz, CDCl3) δ 7.90–7.83 (m, 2H), 7.80–7.72 (m, 2H), 6.54 (d, J = 6.2 Hz, 1H), 3.71–3.62 (m, 2H), 3.57 (dd, J = 5.4, 4.3 Hz, 2H), 3.39 (s, 3H), 1.36 (s, 12H).

[0464] O-(tert-Butyldimethylsilyl)-N-(2-(4-((2-methoxyethyl)carbamoyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (10.2)

[0465]

[0466] Dissolve N-(2-bromothiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (0.656 g, 1.55 mmol) and N-(2-methoxyethyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzamide (0.561 g, 1.84 mmol) in 1,4-dioxane (3 mL). Add potassium carbonate (2 M aqueous solution, 1.50 mL, 3.00 mmol) and bis(triphenylphosphine)palladium(II) chloride (0.114 g, 0.162 mmol), and heat the mixture at 80 °C for 24 h. Cool the mixture to room temperature and stir for 36 h. Add water (25 mL), and extract the mixture with ethyl acetate (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford O-(tert-butyldimethylsilyl)-N-(2-(4-((2-methoxyethyl)carbamoyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.370 g, 46%) as an orange oil.

[0467] 1 H NMR (400 MHz, CDCl3) δ 8.22 (d, J = 8.7 Hz, 1H), 8.16 (s, 1H), 8.08–8.00 (m, 2H), 7.92–7.82 (m, 2H), 6.59 (t, J = 5.2 Hz, 1H), 4.90–4.83 (m, 1H), 4.22 (dd, J = 10.1, 2.6 Hz, 1H), 4.01–3.90 (m, 1H), 3.79 (s, 3H), 3.74–3.65 (m, 2H), 3.60 (dd, J = 5.4, 4.3 Hz, 2H), 3.42 (s, 3H), 0.93 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[0468] O-(tert-butyldimethylsilyl)-N-(2-(4-((2-methoxyethyl)carbamoyl)phenyl)thiazole-4-carbonyl)-L-serine (10.3)

[0469]

[0470] Using the procedure described in Example 9.2, O-(tert-butyldimethylsilyl)-N-(2-(4-((2-methoxyethyl)carbamoyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.370 g, 0.709 mmol) was converted to O-(tert-butyldimethylsilyl)-N-(2-(4-((2-methoxyethyl)carbamoyl)phenyl)thiazole-4-carbonyl)-L-serine (0.287 g, 80%) as an orange solid.

[0471] 1 H NMR (400 MHz, DMSO-d6) δ 8.76 (t, J = 4.8 Hz, 1H), 8.49 (d, J = 7.4 Hz, 1H), 8.26 (d, J = 8.6 Hz, 1H), 8.16–8.10 (m, 2H), 8.10–8.01 (m, 2H), 4.65 (dt, J = 8.6, 3.6 Hz, 1H), 4.16 (dd, J = 10.3, 3.6 Hz, 1H), 4.01 (dd, J = 10.3, 3.7 Hz, 1H), 3.57–3.45 (m, 5H), 3.44–3.35 (m, 2H), 0.93 (s, 9H), 0.11 (s, 3H), 0.09 (s, 3H).

[0472] O-(tert-butyldimethylsilyl)-N-(2-(4-((2-methoxyethyl)carbamoyl)phenyl)thiazole-4-carbonyl)-L-seryl-L-serine methyl ester (10.4)

[0473]

[0474] Using the procedure described for Example 2.7, O-(tert-butyldimethylsilyl)-N-(2-(4-((2-methoxyethyl)carbamoyl)phenyl)thiazole-4-carbonyl)-L-serine (0.287 g, 0.565 mmol) was converted to O-(tert-butyldimethylsilyl)-N-(2-(4-((2-methoxyethyl)carbamoyl)phenyl)thiazole-4-carbonyl)-L-seryl-L-serine methyl ester (0.344 g, 100%) as a white solid.

[0475] 11H NMR (400 MHz, CDCl3) δ 8.25 (d, J = 6.9 Hz, 1H), 8.17 (d, J = 2.1 Hz, 1H), 8.06–7.99 (m, 2H), 7.90–7.82 (m, 2H), 7.44 (d, J = 7.0 Hz, 1H), 6.57 (s, 1H), 4.70 (dt, J = 7.4, 3.8 Hz, 1H), 4.67–4.60 (m, 1H), 4.22 (dd, J = 9.8, 4.1 Hz, 1H), 4.04–3.95 (m, 2H), 3.89–3.81 (m, 1H), 3.79 (d, J = 6.8 Hz, 3H), 3.73–3.65 (m, 2H), 3.60 (dd, J = 5.4, 4.2 Hz, 2H), 3.42 (s, 3H), 0.96 (s, 9H), 0.16 (s, 3H), 0.15 (s, 3H).

[0476] Methyl 2-(2-(2-(4-((2-methoxyethyl)carbamoyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (10)

[0477]

[0478] Using the procedure described for compound 2, (S)-methyl 2-(3-hydroxy-2-(2-(4-((2-methoxyethyl)carbamoyl)phenyl)thiazole-4-carboxamido)propanamido)acrylate (0.212 g, 0.445 mmole) was converted to methyl 2-(2-(2-(4-((2-methoxyethyl)carbamoyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.086 g, 33%).

[0479] 1 1H NMR (400 MHz, CDCl3) δ 10.02 (s, 1H), 8.56 (s, 1H), 8.20 (s, 1H), 8.13–8.05 (m, 2H), 7.94–7.83 (m, 2H), 6.79 (d, J = 2.2 Hz, 1H), 6.72 (s, 1H), 6.58 (d, J = 5.7 Hz, 1H), 6.04 (d, J = 1.3 Hz, 1H), 5.52 (t, J = 1.9 Hz, 1H), 3.91 (s, 3H), 3.75–3.65 (m, 2H), 3.60 (dd, J = 5.4, 4.3 Hz, 2H), 3.42 (s, 3H).

[0480] Compound 11: (R)-2-(2-(2-(3-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido) acrylamido)methyl acrylate

[0481] (R)-Ethyl 2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (11.1)

[0482]

[0483] Dissolve ethyl 2-bromothiazole-4-carboxylate (1.007 g, 4.27 mmol) in N,N-dimethylacetamide (8 mL). Add (R)-tert-butyl piperidin-3-ylcarbamate (0.900 g, 4.49 mmol) and then add triethylamine (0.660 mL, 4.71 mmol). Heat the solution at 70 °C for 3 days and then cool to room temperature. Add water (40 mL) and extract the mixture with ethyl acetate (3 x 15 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford (R)-ethyl 2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (1.032 g, 68%) as a yellow solid.

[0484] 1 1H NMR (400 MHz, chloroform-d) δ 7.44 (s, 1H), 4.69 (s, 1H), 4.35 (q, J = 7.1 Hz, 2H), 3.80 (s, 1H), 3.70 (d, J = 12.8 Hz, 1H), 3.61 (s, 1H), 3.46 (s, 1H), 3.29 (s, 1H), 1.97–1.86 (m, 1H), 1.86–1.76 (m, 1H), 1.76–1.65 (m, 1H), 1.57 (d, J = 24.5 Hz, 1H), 1.45 (s, 9H), 1.37 (t, J = 7.1 Hz, 3H).

[0485] (R)-2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylic acid (11.2)

[0486]

[0487] Using the procedure described for Example 1.3, convert (R)-ethyl 2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (1.032 g, 2.90 mmol) to (R)-2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylic acid (0.847 g, 89%) as a yellow solid.

[0488] 11H NMR (400 MHz, CDCl3) δ 7.51 (s, 1H), 4.66 (s, 1H), 3.86–3.71 (m, 2H), 3.59 (s, 1H), 3.40 (s, 1H), 3.26 (s, 1H), 1.95 (d, J = 4.0 Hz, 1H), 1.85 (ddt, J = 10.4, 7.2, 3.6 Hz, 1H), 1.72 (ddq, J = 13.1, 8.6, 4.0 Hz, 1H), 1.57 (s, 1H), 1.46 (s, 9H).

[0489] (2-((R)-3-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (11.3)

[0490]

[0491] Using the procedure described for Example 1.4, (R)-2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylic acid (0.400 g, 1.22 mmole) was converted to (2-((R)-3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.547 g, 100%) as a white solid.

[0492] 1 1H NMR (400 MHz, CDCl3) δ 8.05 (d, J = 7.8 Hz, 1H), 7.40 (s, 1H), 4.79 (dt, J = 7.6, 3.8 Hz, 1H), 4.65 (s, 1H), 4.09–3.99 (m, 2H), 3.89 (d, J = 12.6 Hz, 1H), 3.81 (s, 4H), 3.54 (s, 1H), 3.39 (s, 1H), 3.13 (dd, J = 12.5, 7.7 Hz, 1H), 1.93 (dd, J = 7.8, 4.5 Hz, 1H), 1.71 (dp, J = 13.5, 4.5 Hz, 1H), 1.56 (d, J = 9.0 Hz, 1H), 1.45 (s, 9H).

[0493] N-(2-((R)-3-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (11.4)

[0494]

[0495] Using the procedure described for Examples 4.2 and 4.3, (2-((R)-3-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.456 g, 1.06 mmole) was converted to N-(2-((R)-3-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (0.510 g, 91%) as a colorless oil.

[0496] 1 H NMR (400 MHz, CDCl3) δ 7.95 (d, J = 7.6 Hz, 1H), 7.42 (s, 1H), 4.78–4.64 (m, 2H), 4.22 (dd, J = 10.1, 3.6 Hz, 1H), 3.90 (dd, J = 10.1, 4.7 Hz, 1H), 3.80 (s, 1H), 3.69 (s, 1H), 3.54 (s, 1H), 3.39 (s, 1H), 3.24 (s, 1H), 1.90 (d, J = 17.3 Hz, 1H), 1.71 (dt, J = 9.0, 4.3 Hz, 1H), 1.45 (s, 10H), 0.91 (d, J = 5.4 Hz, 9H), 0.11 (s, 3H), 0.09 (s, 3H).

[0497] N-(2-((R)-3-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (11.5)

[0498]

[0499] Using the procedure described for Example 2.7, N-(2-((R)-3-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (0.510 g, 0.965 mmole) was converted to N-(2-((R)-3-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (0.401 g, 66%) as a pale yellow oil.

[0500] 11H NMR (400 MHz, CDCl3) δ 7.97 (d, J = 7.1 Hz, 1H), 7.40 (s, 2H), 4.67 (td, J = 8.3, 7.3, 4.8 Hz, 2H), 4.62–4.50 (m, 1H), 4.19 - 4.14 (m, 1H), 3.97 (d, J = 3.7 Hz, 2H), 3.85–3.79 (m, 1H), 3.77 (d, J = 2.6 Hz, 4H), 3.68 (s, 1H), 3.54 (s, 1H), 3.40 (s, 1H), 3.32–3.15 (m, 1H), 1.99–1.87 (m, 1H), 1.71 (d, J = 9.8 Hz, 1H), 1.45 (s, 9H), 0.91 (s, 9H), 0.12 (s, 3H), 0.10 (s, 3H).

[0501] (R)-2-(2-(2-(3-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)methyl acrylate (11)

[0502]

[0503] Using the procedure described for compound 2, methyl 2-((S)-2-(2-((R)-3-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)-3-hydroxypropanamido)acrylate (0.257 g, 0.517 mmole) was converted to methyl (R)-2-(2-(2-(3-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.102 g, 33%).

[0504] 1 1H NMR (400 MHz, CDCl3) δ 9.71 (s, 1H), 8.50 (s, 1H), 7.43 (s, 1H), 6.71 (d, J = 2.1 Hz, 1H), 6.66 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.43 (t, J = 1.9 Hz, 1H), 4.71 (s, 1H), 3.89 (s, 3H), 3.86–3.77 (m, 1H), 3.74–3.64 (m, 1H), 3.59 (s, 1H), 3.47 (s, 1H), 3.30 (s, 1H), 1.98–1.78 (m, 2H), 1.78–1.67 (m, 1H), 1.45 (s, 9H).

[0505] Compound 12: 2-(2-(2-(4-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acry lamido)methyl acrylate

[0506] Ethyl 2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (12.1)

[0507]

[0508] Dissolve ethyl 2-bromothiazole-4-carboxylate (3.007 g, 12.7 mmol) in N,N-dimethylacetamide (13 mL). Add tert-butyl piperidin-4-ylcarbamate (2.668 g, 13.3 mmol) then add trimethylamine (2.00 mL, 14.3 mmol), and heat the mixture at 80 °C for 24 h. Cool the solution to room temperature and add water (50 mL). Extract the mixture with ethyl acetate (3 x 20 mL). Dry the combined organic layers over magnesium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography to afford ethyl 2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (3.562 g, 79%) as a white solid.

[0509] 1 H NMR (400 MHz, CDCl3): δ 7.43 (s, 1H), 4.48 (s, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.05–3.92 (m, 2H), 3.68 (s, 1H), 3.15 (ddd, J = 13.2, 11.6, 3.0 Hz, 2H), 2.05 (m, 2H), 1.56–1.47 (m, 2H), 1.45 (s, 9H), 1.37 (t, J = 7.1 Hz, 3H).

[0510] 2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylic acid (12.2)

[0511]

[0512] Use the procedure described in Example 1.3 to convert ethyl 2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (3.562 g, 10.0 mmol) to 2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylic acid (2.994 g, 91%) as a yellow solid.

[0513] 11H NMR (400 MHz, CDCl3): δ 7.52 (s, 1H), 4.50 (s, 1H), 3.95 (dt, J = 13.5, 3.9 Hz, 2H), 3.79–3.62 (m, 1H), 3.18 (ddd, J = 13.3, 11.6, 3.0 Hz, 2H), 2.10–2.02 (m, 2H), 1.58–1.48 (m, 2H), 1.46 (s, 9H).

[0514] N-(2-(4-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (12.3)

[0515]

[0516] Dissolve 2-(4-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylic acid (0.500 g, 1.53 mmole) in DCM (3 mL). Add N,N'-carbonyldiimidazole (0.262 g, 1.62 mmole) portionwise (gas evolution was observed), and stir the mixture at room temperature for 60 minutes. Add L-serine methyl ester hydrochloride (0.262 g, 1.68 mmole) and N,N-diisopropylethylamine (0.320 mL, 1.84 mmole), and stir the solution at room temperature for 18 hours. Add water (25 mL), and extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Dissolve the residue in DCM (5 mL). Add imidazole (0.116 g, 1.70 mmole) and tert-butyldimethylchlorosilane (0.256 g, 1.70 mmole), and stir the mixture at room temperature for 90 minutes. Add water (25 mL), and extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate to afford N-(2-(4-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (0.994 g) as a pale yellow slurry.

[0517] 11H NMR (400 MHz, CDCl3): δ 7.95 (d, J = 8.8 Hz, 1H), 7.37 (s, 1H), 4.78 (ddd, J = 8.8, 3.4, 2.5 Hz, 1H), 4.50 (s, 1H), 4.16 (dd, J = 10.0, 2.6 Hz, 1H), 4.03–3.92 (m, 2H), 3.92–3.84 (m, 2H), 3.76 (s, 3H), 3.71 (d, J = 15.5 Hz, 1H), 3.22–3.06 (m, 2H), 2.09–1.99 (m, 2H), 1.58–1.48 (m, 2H), 1.46 (s, 9H), 0.88 (s, 9H), 0.05 (s, 3H), 0.03 (s, 3H).

[0518] N-(2-(4-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (12.4)

[0519]

[0520] Using the procedure described in Example 4.3, N-(2-(4-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (0.994 g, 1.83 mmole) was converted to N-(2-(4-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (0.900 g) as a yellow oil.

[0521] 1 1H NMR (400 MHz, CDCl3): δ 7.97 (d, J = 7.9 Hz, 1H), 7.41 (d, J = 8.3 Hz, 1H), 4.75 (s, 1H), 4.54 (s, 1H), 4.22 (dd, J = 10.0, 3.2 Hz, 1H), 3.92 (ddd, J = 14.3, 8.6, 3.7 Hz, 3H), 3.80–3.63 (m, 1H), 3.22–3.06 (m, 2H), 2.08 - 1.99 (m, 2H), 1.42 (m, 11H), 0.90 (s, 9H), 0.08 (s, 6H).

[0522] O-Acetyl-N-(N-(2-(4-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (12.5)

[0523]

[0524] Dissolve N-(2-(4-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (0.900 g, 1.70 mmol) in DCM (4 mL), and add N,N’-carbonyldiimidazole (0.306 g, 1.89 mmol) in portions (gas evolution was observed). Stir the solution at room temperature for 60 minutes, and add L-serine methyl ester hydrochloride (0.293 g, 1.88 mmol) and N,N-diisopropylethylamine (0.360 mL, 2.07 mmol). Stir the solution at room temperature for 2 hours, and add water (25 mL). Extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Dissolve the residue in DCM (4 mL), and add triethylamine (0.270 mL, 1.93 mmol) and acetic anhydride (0.180 mL, 1.90 mmol). Stir the solution at room temperature for 18 hours, and add water (25 mL). Extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford O-acetyl-N-(N-(2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (0.455 g, 40%) as a yellow oil.

[0525] 1H NMR (400 MHz, CDCl3): δ 7.99 (d, 1H), 7.41 (d, 1H), 7.39 (s, 1H), 4.84 (m, 1H), 4.55 (m, 1H), 4.49–4.20 (m, 2H), 4.28 (dd, 1H), 4.19 (dd, 1H), 4.00–3.87 (m, 2H), 3.75 (s, 3H), 3.74–3.59 (m, 2H), 3.21–3.07 (m, 2H), 2.03 (s, 3H), 1.52–1.47 (m, 2H), 1.45 (s, 9H), 0.91 (s, 9H), 0.12 (s, 3H), 0.11 (s, 3H).

[0526] (S)-2-(2-(2-(4-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)-3-hydroxypropanamido)methyl acrylate (12.6)

[0527]

[0528] Dissolve O-acetyl-N-(N-(2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (0.455 g, 0.677 mmole) in THF (1.5 mL). Add tetrabutylammonium fluoride (1 M solution in THF, 2.00 mL, 2.00 mmole), and stir the solution at room temperature for 5 h. Add water (25 mL), and extract the mixture with ethyl acetate (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate to afford methyl (S)-2-(2-(2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)-3-hydroxypropanamido)acrylate (0.347 g) as a thick yellow oil.

[0529] 1 H NMR (400 MHz, CDCl3): δ 9.07 (s, 1H), 8.07 (d, J = 7.6 Hz, 1H), 7.43 (d, J = 11.8 Hz, 1H), 6.56 (s, 1H), 5.94 (d, J = 1.4 Hz, 1H), 4.70 (ddd, J = 7.8, 5.1, 3.2 Hz, 1H), 4.53 (s, 1H), 4.26 (dd, J = 11.5, 3.2 Hz, 1H), 4.02–3.90 (m, 3H), 3.83 (s, 3H), 3.81–3.73 (m, 1H), 3.67 (d, J = 19.7 Hz, 1H), 3.21–3.07 (m, 2H), 2.07 (d, J = 16.5 Hz, 2H), 1.51–1.47 (m, 2H), 1.46 (s, 9H).

[0530] Methyl 2-(2-(2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (12)

[0531]

[0532] (S)-Methyl 2-(2-(2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)-3-hydroxypropanamido)acrylate (0.347 g, 0.697 mmol) was dissolved in DCM (1.5 mL) and cooled to 0 °C. Triethylamine (0.150 mL, 1.07 mmol) was added followed by methanesulfonyl chloride (0.080 mL, 1.03 mmol), and the mixture was stirred at 0 °C for 90 minutes. Water (25 mL) was added, and the mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated. The residue was dissolved in THF (1.5 mL) and cooled to 0 °C. 1,8-Diazabicyclo[5.4.0]undec-7-ene (0.160 mL, 1.07 mmol) was added, and the solution was stirred at 0 °C for 90 minutes. Water (25 mL) was added, and the mixture was extracted with ethyl acetate (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography to afford methyl 2-(2-(2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (0.124 g, 38% (from 27.5)) as a white solid. 1 H NMR (400 MHz, CDCl3): δ 9.71 (s, 1H), 8.51 (s, 1H), 7.42 (s, 1H), 6.71 (d, J = 2.1 Hz, 1H), 6.66 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.43 (t, J = 1.9 Hz, 1H), 4.49 (s, 1H), 4.03–3.93 (m, 2H), 3.89 (s, 3H), 3.70 (s, 1H), 3.23–3.10 (m, 2H), 2.12–2.04 (m, 2H), 1.57–1.48 (m, 2H), 1.46 (s, 9H).

[0533] Compound 13: 2-(2-(2-(4-(6-((tert-Butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-meth yl)carbamoyl)acrylamido)methyl acrylate

[0534] Ethyl 2-(4-(6-((tert-butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carboxylate (13.1)

[0535]

[0536] Dissolve ethyl 2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (Example 12.1, 7.176 g, 20.2 mmole) in DCM (40 mL). Add HCl (4 M solution in 1,4-dioxane, 20.0 mL, 80.0 mmole), and stir the mixture at room temperature for 60 minutes, then concentrate.

[0537] In a separate flask, dissolve 6-((tert-butoxycarbonyl)amino)hexanoic acid (5.141 g, 22.2 mmole) in DCM (40 mL). Add N,N’-carbonyldiimidazole (3.765 g, 23.2 mmole) in portions (gas evolution was observed), and stir the solution at room temperature for 90 minutes. Add the solution to the hydrochloride amine generated above, and add N,N-diisopropylethylamine (4.20 mL, 24.1 mmole). Stir the resulting solution at room temperature for 18 hours. Add water (100 mL) and separate the two layers. Extract the aqueous layer with DCM (2 x 20 mL). Dry the combined organic matter over sodium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford ethyl 2-(4-(6-((tert-butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carboxylate (8.120 g, 86%) as a pale yellow solid.

[0538] 1 1H NMR (400 MHz, CDCl3): δ 7.43 (d, J = 1.5 Hz, 1H), 5.66 (d, J = 7.9 Hz, 1H), 4.60 (s, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.06–3.94 (m, 3H), 3.21–3.13 (m, 2H), 3.13–3.04 (m, 3H), 2.17 (t, J = 7.6 Hz, 2H), 2.06–1.99 (m, 2H), 1.65 (p, J = 7.5 Hz, 2H), 1.54–1.47 (m, 3H), 1.44 (s, 9H), 1.40–1.29 (m, 5H).

[0539] 2-(4-(6-((tert-butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carboxylic acid (13.2)

[0540]

[0541] Using the procedure described in Example 1.3, ethyl 2-(4-(6-((tert-butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carboxylate (8.120 g, 17.3 mmole) was converted to 2-(4-(6-((tert-butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carboxylic acid (9.950 g) as a golden oil and carried forward without further purification.

[0542] N-(2-(4-(6-((tert-butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (13.3)

[0543]

[0544] Using the procedure described in Example 12.3, 2-(4-(6-((tert-butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carboxylic acid (9.950 g, 22.6 mmole) was converted to N-(2-(4-(6-((tert-butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (6.704 g, 59% from 29.1) as a yellow oil.

[0545] 1 H NMR (400 MHz, CDCl3): δ 7.95 (d, J = 8.8 Hz, 1H), 7.38 (s, 1H), 5.60–5.49 (m, 1H), 4.78 (ddd, J = 8.8, 3.3, 2.5 Hz, 1H), 4.58 (s, 1H), 4.20–4.15 (m, 1H), 4.03 (tdd, J = 11.4, 7.8, 4.0 Hz, 2H), 3.97–3.90 (m, 1H), 3.88 (dd, J = 10.0, 3.4 Hz, 1H), 3.76 (s, 3H), 3.21–3.13 (m, 2H), 3.11 (dq, J = 7.7, 5.5, 3.7 Hz, 2H), 2.17 (t, J = 7.6 Hz, 2H), 2.05 (m, 2H), 1.73–1.60 (m, 2H), 1.57–1.46 (m, 4H), 1.44 (s, 9H), 1.40–1.31 (m, 2H), 0.88 (s, 9H), 0.05 (s, 3H), 0.02 (s, 3H).

[0546] N-(2-(4-(6-((tert-butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (13.4)

[0547]

[0548] Dissolve N-(2-(4-(6-((tert-Butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (6.704 g, 10.2 mmole) in 4 / 1 / 1 THF / methanol / water (30 mL). Add lithium hydroxide (0.738 g, 30.8 mmole), and stir the mixture at room temperature for 2 hours. Add water (100 mL), and treat the solution with 1 N hydrochloric acid to pH = 4. Extract the mixture with diethyl ether (4 x 25 mL) and ethyl acetate (1 x 25 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate to afford N-(2-(4-(6-((tert-Butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine.

[0549] Dissolve N-(2-(4-(6-((tert-Butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (0.505 g, 0.787 mmole) in DCM (1.6 mL). Add L-serine methyl ester hydrochloride (0.292 g, 1.88 mmole) then add N,N-diisopropylethylamine (0.270 mL, 1.55 mmole) and pyBOP (0.490 g, 0.942 mmole). Stir the mixture at room temperature for 4 hours, and add water (25 mL). Extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford N-(2-(4-(6-((tert-Butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (0.401 g, 69%) as a thick colorless gel.

[0550] 1H NMR (400 MHz, CDCl3): δ 9.07 (s, 1H), 8.05 (d, J = 8.8 Hz, 1H), 7.48 (s, 1H), 6.54 (s, 1H), 5.96 (s, 1H), 5.53–5.47 (m, 1H), 4.72–4.69 (m, 1H), 4.63–4.57 (m, 2H), 4.29–4.22 (m, 1H), 4.09–3.92 (m, 4H), 3.81 (s, 3H), 3.79–3.75 (m, 1H), 3.22–3.17 (m, 2H), 3.16–3.05 (m, 2H), 2.20 (t, J = 7.5 Hz, 2H), 2.05–1.97 (m, 2H), 1.70–1.59 (m, 2H), 1.51–1.40 (m, 4H), 1.43 (s, 9H), 1.38–1.27 (m, 2H).

[0551] (S)-2-(2-(2-(4-(6-((tert-Butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carboxamido)-3-hydroxypropanamido)methyl acrylate (13)

[0552]

[0553] Dissolve N-(2-(4-(6-((tert-Butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (0.401 g, 0.540 mmol) in DCM (2 mL). Add triethylamine (0.084 mL, 0.599 mmol) and acetic anhydride (0.060 mL, 0.635 mmol), and stir the mixture at room temperature for 18 h. Add water (25 mL), and extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Dissolve the residue in THF, and add tetrabutylammonium fluoride (1 M solution in THF, 1.60 mL, 1.60 mmol). Stir the solution at room temperature for 2 h and add water (25 mL). Extract the mixture with ethyl acetate (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate to afford (S)-2-(2-(2-(4-(6-((tert-Butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carboxamido)-3-hydroxypropanamido)methyl acrylate (0.318 g, 96%) as a white solid.

[0554] Methyl (S)-2-(2-(2-(4-(6-((tert-butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carboxamido)-3-hydroxypropanamido)acrylate (0.318 g, 0.521 mmol) was dissolved in DCM (2 mL) and cooled to 0 °C. Triethylamine (0.110 mL, 0.785 mmol) was added and then methanesulfonyl chloride (0.060 mL, 0.775 mmol) was added. The mixture was stirred at 0 °C for 2 h and water (25 mL) was added. The mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The residue was dissolved in THF (2 mL) and cooled to 0 °C. 1,8-Diazabicyclo[5.4.0]undec-7-ene (0.120 mL, 0.802 mmol) was added and the solution was stirred at 0 °C for 2 h. Water (25 mL) was added and the mixture was extracted with ethyl acetate (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford methyl 2-(2-(2-(4-(6-((tert-butoxycarbonyl)amino)hexanamido)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (0.106 g, 34%) as a white solid.

[0555] 1 1H NMR (400 MHz, CDCl3): δ 9.71 (s, 1H), 8.51 (s, 1H), 7.43 (s, 1H), 6.72 (d, J = 2.1 Hz, 1H), 6.66 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.47–5.36 (m, 2H), 4.54 (s, 1H), 4.07–3.95 (m, 3H), 3.89 (s, 3H), 3.22–3.05 (m, 4H), 2.17 (t, J = 7.5 Hz, 2H), 2.10–2.00 (m, 2H), 1.66 (p, J = 7.4 Hz, 2H), 1.51 (h, J = 7.5 Hz, 4H), 1.43 (s, 9H), 1.40–1.30 (m, 2H).

[0556] Compound 14: 3-(4-((3-((3-Methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en- 2-yl)carbamoyl)thiazol-2-yl)phenylcarboxylic acid tert-butyl ester

[0557] tert-Butyl 3-thiocarbamoylbenzoate (14.1)

[0558]

[0559] Dissolve tert-butyl 3-cyanobenzoate (11.887 g, 58.5 mmol) prepared as described in Adv. Synth. Catal., 2014, 356 (14 - 15), 3074 - 3082 in pyridine (60 mL). Add triethylamine (9.00 mL, 64.2 mmol) and then add ammonium sulfide (40% aqueous solution, 12.0 mL, 70.2 mmol), and heat the mixture to 50 °C for 4 h. Cool the mixture to room temperature and concentrate. Dissolve the residue in ethyl acetate (75 mL) and wash successively with 0.5 N hydrochloric acid (3 x 50 mL), saturated aqueous sodium bicarbonate (1 x 25 mL), and saturated aqueous sodium chloride (1 x 25 mL). Dry the organic layer over magnesium sulfate, filter, and concentrate to afford tert-butyl 3-thiocarbamoylbenzoate (11.043 g, 68%) as a yellow solid.

[0560] 1 1H NMR (400 MHz, DMSO-d6): δ 10.02 (s, 1H), 9.68 (s, 1H), 8.41 (td, J = 1.9, 0.5 Hz, 1H), 8.07 (ddd, J = 7.8, 2.0, 1.2 Hz, 1H), 8.01 (ddd, J = 7.8, 1.8, 1.2 Hz, 1H), 7.55 (td, J = 7.8, 0.5 Hz, 1H), 1.57 (s, 9H).

[0561] Ethyl 2-(3-(tert-butoxycarbonyl)phenyl)thiazole-4-carboxylate (14.2)

[0562]

[0563] Dissolve tert-butyl 3-thiocarbamoylbenzoate (11.043 g, 46.5 mmol) in 1,4-dioxane (235 mL) and cool to 0 °C. Add potassium bicarbonate (37.398 g, 374 mmol) then add ethyl bromopyruvate (11.7 mL, 93.2 mmol). Stir the mixture vigorously at 0 °C for 2 h, then stir vigorously at room temperature for 18 h. Concentrate the mixture and dissolve the residue in water (200 mL) and ethyl acetate (100 mL). Separate the two layers and extract the aqueous layer with ethyl acetate (2 x 100 mL). Wash the combined organic layers with saturated aqueous sodium chloride (1 x 100 mL), dry over magnesium sulfate, filter and concentrate. Dissolve the residue in 1,4-dioxane (235 mL) and cool to 0 °C. Add pyridine (30.0 mL, 371 mmol), then slowly add trifluoroacetic anhydride (19.5 mL, 140 mmol), and stir the solution at 0 °C for 90 min, then at room temperature for 2 h. Concentrate the mixture and dissolve the residue in ethyl acetate (300 mL). Wash the solution successively with 1 N hydrochloric acid (3 x 50 mL), saturated aqueous sodium bicarbonate (1 x 50 mL) and saturated aqueous sodium chloride (1 x 50 mL). Dry the organic layer over magnesium sulfate, filter and concentrate. Divide the crude residue into two portions and purify each by silica gel chromatography. Combine and concentrate the fractions containing the desired product to afford ethyl 2-(3-(tert-butoxycarbonyl)phenyl)thiazole-4-carboxylate (17.31 g) as an orange oil.

[0564] 1 H NMR (400 MHz, CDCl3): δ 8.55–8.48 (m, 1H), 8.23 (ddd, J = 7.8, 1.9, 1.2 Hz, 1H), 8.20 (s, 1H), 8.08 (dt, J = 7.8, 1.4 Hz, 1H), 7.53 (td, J = 7.8, 0.6 Hz, 1H), 4.46 (q, J = 7.1 Hz, 2H), 1.63 (s, 9H), 1.44 (d, J = 14.3 Hz, 3H).

[0565] 2-(3-(tert-Butoxycarbonyl)phenyl)thiazole-4-carboxylic acid (14.3)

[0566]

[0567] Ethyl 2-(3-(tert-butoxycarbonyl)phenyl)thiazole-4-carboxylate (17.31 g, 51.9 mmol) was dissolved in 4 / 1 / 1 THF / methanol / water (200 mL). Lithium hydroxide (3.733 g, 156 mmol) was added and the mixture was stirred vigorously at room temperature for 2 h. The mixture was filtered and the filtrate was stirred with additional lithium hydroxide (ca. 0.5 g) for 60 min and then concentrated to the aqueous layer. Water (200 mL) was added and the mixture was combined with the solid from above. The mixture was treated with 6 N hydrochloric acid to pH = 4. The solid was collected by filtration and washed with water and then allowed to air dry to afford 2-(3-(tert-butoxycarbonyl)phenyl)thiazole-4-carboxylic acid as a white solid (16.847 g).

[0568] 1 H NMR (400 MHz, DMSO-d6): δ 8.42 (t, J = 1.7 Hz, 1H), 8.21 (ddd, J = 7.8, 1.9, 1.1 Hz, 1H), 7.99 (dt, J = 7.8, 1.3 Hz, 1H), 7.94 (s, 1H), 7.64 (t, J = 7.8 Hz, 1H), 1.59 (s, 9H).

[0569] (S)-tert-Butyl 3-(4-((3-((tert-butyldimethylsilyl)oxy)-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)benzoate (14.4)

[0570]

[0571] 2-(3-(tert-Butoxycarbonyl)phenyl)thiazole-4-carboxylic acid (16.847 g, 55.2 mmol) was suspended in DMF (220 mL). L-Serine methyl ester hydrochloride (10.357 g, 66.6 mmol) was added followed by 1-hydroxybenzotriazole hydrate (9.312 g, 60.8 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (11.664 g, 60.8 mmol) and N,N-diisopropylethylamine (29.0 mL, 166 mmol). The mixture was stirred at room temperature for 18 h, and water (300 mL) and 1 N hydrochloric acid (200 mL) were added. The mixture was extracted with ethyl acetate (4 x 100 mL). The combined organic layers were washed with saturated aqueous sodium chloride (1 x 100 mL), dried over magnesium sulfate, filtered and concentrated. The residue was dissolved in DCM (110 mL), and imidazole (4.160 g, 61.1 mmol) and tert-butyldimethylchlorosilane (9.158 g, 60.8 mmol) were added. The mixture was stirred at room temperature for 90 min, and water (300 mL) was added. The two layers were separated, and the aqueous layer was extracted with DCM (2 x 50 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford tert-butyl (S)-3-(4-((3-((tert-butyldimethylsilyl)oxy)-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)benzoate (15.343 g, 63% from intermediate 30.2) as a white solid.

[0572] 1 H NMR (400 MHz, CDCl3): δ 8.52–8.44 (m, 1H), 8.21 (ddd, J = 7.8, 1.9, 1.2 Hz, 2H), 8.14 (s, 1H), 8.07 (dt, J = 7.8, 1.4 Hz, 1H), 7.52 (td, J = 7.8, 0.6 Hz, 1H), 4.87 (dt, J = 8.7, 3.1 Hz, 1H), 4.21 (dd, J = 10.1, 2.8 Hz, 1H), 3.96 (dd, J = 10.0, 3.4 Hz, 1H), 3.79 (s, 3H), 1.64 (s, 9H), 0.91 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[0573] N-(2-(3-(tert-Butoxycarbonyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (14.5)

[0574]

[0575] (S)-tert-Butyl 3-(4-((3-((tert-butyldimethylsilyl)oxy)-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)benzoate (15.343 g, 29.5 mmol) was dissolved in 4 / 1 / 1 THF / methanol / water (90 mL). Lithium hydroxide (1.425 g, 59.5 mmol) was added and the mixture was stirred at room temperature for 3 h. Water (300 mL) was added and the mixture was treated with 1 N hydrochloric acid to pH = 4. The mixture was extracted with ethyl acetate (4 x 75 mL). The combined organics were dried over magnesium sulfate, filtered and concentrated to afford N-(2-(3-(tert-butoxycarbonyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine as a white solid (14.560 g, 97%).

[0576] 1 H NMR (400 MHz, DMSO-d6): δ 8.46 (d, J = 9.3 Hz, 2H), 8.25–8.15 (m, 2H), 8.03 (dt, J = 7.8, 1.3 Hz, 1H), 7.69 (dt, J = 9.7, 7.7 Hz, 1H), 4.60 (dt, J = 8.4, 3.5 Hz, 1H), 4.11 (dd, J = 10.3, 3.5 Hz, 1H), 3.97 (dd, J = 10.4, 3.6 Hz, 1H), 1.58 (s, 9H), 0.85 (s, 9H), 0.05 (s, 3H), 0.03 (s, 3H).

[0577] tert-Butyl 3-(4-(((4S,7S)-4-(hydroxymethyl)-10,10,11,11-tetramethyl-3,6-dioxo-2,9-dioxa-5-azadisiloxan-7-yl)carbamoyl)thiazol-2-yl)benzoate (14.6)

[0578]

[0579] Dissolve N-(2-(3-(tert-butoxycarbonyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (3.142 g, 6.20 mmol) in DCM (12 mL). Add L-serine methyl ester hydrochloride (1.110 g, 7.13 mmol) and then add N,N-diisopropylethylamine (2.10 mL, 12.1 mmol), HOBt·H2O (1.099 g, 7.18 mmol), and EDC·HCl (1.371 g, 7.15 mmol). Stir the mixture at room temperature for 18 h. Add water (50 mL) and separate the two layers. Extract the aqueous layer with DCM (2 x 15 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford tert-butyl 3-(4-(((4S,7S)-4-(hydroxymethyl)-10,10,11,11-tetramethyl-3,6-dioxo-2,9-dioxa-5-aza-10-silaundecan-7-yl)carbamoyl)thiazol-2-yl)benzoate (2.159 g, 57%).

[0580] 1 1H NMR (400 MHz, CDCl3): δ 8.49–8.41 (m, 1H), 8.28–8.21 (m, 1H), 8.21–8.16 (m, 1H), 8.14 (s, 1H), 8.06 (dq, J = 7.8, 1.7 Hz, 1H), 7.56–7.45 (m, 2H), 4.68 (tdd, J = 11.3, 8.0, 4.0 Hz, 2H), 4.20 (dt, J = 9.8, 4.3 Hz, 1H), 4.05–3.94 (m, 2H), 3.90–3.82 (m, 1H), 3.78 (d, J = 7.9 Hz, 3H), 1.63 (d, J = 1.0 Hz, 9H), 0.94 (d, J = 1.2 Hz, 9H), 0.14 (d, J = 1.2 Hz, 3H), 0.14 (s, 3H), 0.13 (s, 3H).

[0581] tert-Butyl 3-(4-(((S)-3-hydroxy-1-(((S)-3-hydroxy-1-methoxy-1-oxopropan-2-yl)amino)-1-oxopropan-2-yl)amino)carbamoyl)thiazol-2-yl)benzoate (14.7)

[0582]

[0583] Dissolve tert-butyl 3-(4-(((4S,7S)-4-(hydroxymethyl)-10,10,11,11-tetramethyl-3,6-dioxo-2,9-dioxa-5-aza-10-sila-dodecan-7-yl)carbamoyl)thiazol-2-yl)benzoate (2.159 g, 3.55 mmol) in THF (7 mL). Add tetrabutylammonium fluoride (1 M solution in THF, 3.90 mL, 3.90 mmol), and stir the solution at room temperature for 2 1 / 2 h. Add water (50 mL), and extract the mixture with ethyl acetate (3 x 15 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford tert-butyl 3-(4-(((S)-3-hydroxy-1-(((S)-3-hydroxy-1-methoxy-1-oxopropan-2-yl)amino)-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)benzoate (1.346 g, 77%) as a white solid.

[0584] 1 1H NMR (400 MHz, CDCl3): δ 8.44–8.36 (m, 2H), 8.17–8.09 (m, 2H), 8.03 (d q, J = 7.8, 1.2 Hz, 1H), 7.90 (d, J = 7.9 Hz, 1H), 7.49 (t, J = 7.7 Hz, 1H), 4.92–4.80 (m, 1H), 4.75 (d q, J = 7.5, 3.6 Hz, 1H), 4.17–4.10 (m, 1H), 4.05 (ddd, J = 11.6, 7.4, 3.5 Hz, 2H), 3.93 (td, J = 11.3, 10.1, 6.8 Hz, 1H), 3.81 (s, 3H), 1.63 (s, 9H).

[0585] tert-Butyl 3-(4-((3-((3-methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)benzoate (14)

[0586]

[0587] tert-Butyl 3-(4-(((S)-3-hydroxy-1-(((S)-3-hydroxy-1-methoxy-1-oxopropan-2-yl)amino)-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)benzoate (0.200 g, 0.405 mmol) was dissolved in DCM (1 mL) and cooled to 0 °C. Triethylamine (0.285 mL, 2.03 mmol) was added followed by methanesulfonyl chloride (0.160 mL, 2.07 mmol). The mixture was stirred at 0 °C for 60 minutes. Water (25 mL) was added and the mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The residue was dissolved in THF and cooled to 0 °C. 1,8-Diazabicyclo[5.4.0]undec-7-ene (0.300 mL, 2.01 mmol) was added and the solution was stirred at 0 °C for 90 minutes. Water (25 mL) was added and the mixture was extracted with ethyl acetate (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford tert-Butyl 3-(4-((3-((3-methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)benzoate (0.0338 g, 18%) as a colorless oil.

[0588] 1 1H NMR (400 MHz, CDCl3): δ 10.06 (s, 1H), 8.56 (t, J = 1.8 Hz, 2H), 8.24 (ddd, J = 7.8, 1.9, 1.2 Hz, 1H), 8.18 (s, 1H), 8.09 (dt, J = 7.8, 1.4 Hz, 1H), 7.55 (t, J = 7.8 Hz, 1H), 6.78 (d, J = 2.2 Hz, 1H), 6.71 (s, 1H), 6.02 (d, J = 1.3 Hz, 1H), 5.51 (t, J = 1.9 Hz, 1H), 3.91 (s, 3H), 1.65 (s, 9H).

[0589] Compound 15: 2-(2-(2-(4-((2-((tert-Butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl) Methyl (thiazol-4-ylcarbamoyl)acrylamido)acrylate

[0590] Benzyl 4-((2-((tert-butoxycarbonyl)amino)ethyl)carbamoyl)piperidine-1-carboxylate (15.1)

[0591]

[0592] Dissolve 1-((benzyloxy)carbonyl)piperidine-4-carboxylic acid (2.006 g, 7.62 mmol) in DCM (15 mL). Add N,N'-carbonyldiimidazole (1.290 g, 7.96 mmol) in portions (gas evolution was observed), and stir the solution at room temperature for 60 minutes. Slowly add (2-aminoethyl)carbamic acid tert-butyl ester (1.374 g, 8.58 mmol), and stir the solution at room temperature for 2 hours. Add water (50 mL) and separate the two layers. Extract the aqueous layer with DCM (2 x 15 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford benzyl 4-((2-((tert-butoxycarbonyl)amino)ethyl)carbamoyl)piperidine-1-carboxylate (2.984 g, 97%) as a white solid.

[0593] 1 H NMR (400 MHz, CDCl3): δ 7.41–7.28 (m, 5H), 6.43 (s, 1H), 5.12 (s, 2H), 4.92 (s, 1H), 4.20 (s, 2H), 3.40–3.23 (m, 4H), 2.83 (s, 2H), 2.24 (tt, J = 11.5, 3.8 Hz, 1H), 1.84 (d, J = 14.9 Hz, 2H), 1.64 (qd, J = 11.7, 4.0 Hz, 2H), 1.43 (s, 9H).

[0594] (2-(Piperidine-4-carboxamido)ethyl)carbamic acid tert-butyl ester (15.2)

[0595]

[0596] Add palladium on carbon (10%, Degussa type, 0.818 g, 0.769 mmol) to benzyl 4-((2-((tert-butoxycarbonyl)amino)ethyl)carbamoyl)piperidine-1-carboxylate (2.984 g, 7.36 mmol). Add ethanol (15 mL) dropwise on top of the palladium to wet the catalyst, then slowly add the remaining ethanol. Add ammonium formate (0.934 g, 14.8 mmol), and heat the mixture to 70 °C for 4 hours, then cool to room temperature and dilute with DCM (30 mL). Filter the mixture through a pad of diatomaceous earth, and wash the cake with DCM. Concentrate the combined filtrates to afford (2-(piperidine-4-carboxamido)ethyl)carbamic acid tert-butyl ester (2.184 g) as a brown solid.

[0597] 11H NMR (400 MHz, CDCl3): δ 6.40 (s, 1H), 5.08 (s, 1H), 3.40–3.31 (m, 2H), 3.31–3.22 (m, 2H), 3.12 (dt, J = 12.9, 3.7 Hz, 2H), 2.61 (td, J = 12.3, 2.6 Hz, 2H), 2.22 (tt, J = 11.8, 3.7 Hz, 1H), 1.87–1.77 (m, 2H), 1.65–1.51 (m, 2H), 1.40 (d, J = 7.0 Hz, 9H).

[0598] Ethyl 2-(4-((2-((tert-butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxylate (15.3)

[0599]

[0600] Dissolve tert-butyl ((2-(piperidine-4-carboxamido)ethyl)carbamate (2.184 g, 8.05 mmol) in N,N-dimethylacetamide (16 mL). Add ethyl 2-bromothiazole-4-carboxylate (1.913 g, 8.10 mmol) then add triethylamine (1.25 mL, 8.92 mmol), and heat the mixture at 80 °C for 24 h. Cool the mixture to room temperature and add water (75 mL). Extract the mixture with ethyl acetate (3 x 20 mL), and dry, filter, and concentrate the combined organics over magnesium sulfate. Purify the crude residue by silica gel chromatography to afford ethyl 2-(4-((2-((tert-butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxylate (2.174 g, 63%) as a pale yellow solid.

[0601] 1 1H NMR (400 MHz, CDCl3): δ 7.44 (s, 1H), 6.57 (s, 1H), 4.96 (s, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.08 (dt, J = 13.3, 3.6 Hz, 2H), 3.41–3.32 (m, 2H), 3.29 (q, J = 5.7 Hz, 2H), 3.11–3.02 (m, 2H), 2.31 (tt, J = 11.5, 3.7 Hz, 1H), 2.02–1.90 (m, 2H), 1.89–1.77 (m, 2H), 1.44 (s, 9H), 1.37 (t, J = 7.1 Hz, 3H).

[0602] 2-(4-((2-((tert-butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxylic acid (15.4)

[0603]

[0604] Ethyl 2-(4-((2-((tert-Butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxylate (2.174 g, 5.10 mmol) was dissolved in 4 / 1 / 1 THF / methanol / water (15 mL). Lithium hydroxide (0.248 g, 10.4 mmol) was added and the mixture was stirred at room temperature for 2 h. Water (75 mL) was added and the solution was treated with 1 N hydrochloric acid to pH = 4. The mixture was extracted with ethyl acetate (3 x 20 mL). A solid began to precipitate from the organic phase and was collected by filtration and allowed to air dry to afford 2-(4-((2-((tert-Butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxylic acid as a yellow solid. The filtrate was dried over magnesium sulfate, filtered and concentrated to afford a second crop of 2-(4-((2-((tert-Butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxylic acid. The two crops were combined (yellow solid, 1.346 g, 66%).

[0605] 1 H NMR (400 MHz, DMSO-d6): δ 12.58 (s, 1H), 7.85 (t, J = 5.7 Hz, 1H), 7.61 (s, 1H), 6.79 (t, J = 5.7 Hz, 1H), 3.89 (dt, J = 12.9, 3.6 Hz, 2H), 3.06 (dt, J = 12.2, 4.9 Hz, 4H), 3.01–2.88 (m, 2H), 2.34 (tt, J = 11.3, 3.4 Hz, 1H), 1.87–1.71 (m, 2H), 1.67–1.49 (m, 2H), 1.37 (s, 9H).

[0606] N-(2-(4-((2-((tert-Butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (15.5)

[0607]

[0608] Using the procedure described in Example 12.3, 2-(4-((2-((tert-Butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxylic acid (1.346 g, 3.38 mmol) was converted to N-(2-(4-((2-((tert-Butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (1.977 g, 95%) as a thick yellow oil.

[0609] 1 1H NMR (400 MHz, CDCl3): δ 7.96 (d, J = 8.8 Hz, 1H), 7.38 (s, 1H), 6.54 (s, 1H), 4.94 (s, 1H), 4.83–4.73 (m, 1H), 4.20–4.14 (m, 1H), 4.08–3.95 (m, 2H), 3.88 (dd, J = 10.0, 3.4 Hz, 1H), 3.76 (s, 3H), 3.41–3.33 (m, 2H), 3.30 (q, J = 5.8, 4.9 Hz, 2H), 3.11–2.97 (m, 2H), 2.31 (tt, J = 11.5, 3.7 Hz, 1H), 1.95 (dd, J = 13.4, 3.4 Hz, 2H), 1.89–1.75 (m, 2H), 1.45 (s, 9H), 0.88 (s, 9H), 0.05 (s, 3H), 0.03 (s, 3H).

[0610] O-Acetyl-N-(N-(2-(4-((2-((tert-butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (15.6)

[0611]

[0612] N-(2-(4-((2-((tert-Butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (1.977 g, 3.22 mmole) was dissolved in 4 / 1 / 1 THF / methanol / water (9 mL). Lithium hydroxide (0.157 g, 6.56 mmole) was added and the mixture was stirred at room temperature for 3 hours. Water (50 mL) was added and the solution was treated with 1 N hydrochloric acid to pH = 4. The mixture was extracted with ethyl acetate (3 x 15 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated to afford N-(2-(4-((2-((tert-butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (1.894 g, 98%) as a white solid.

[0613] N-(2-(4-((2-((tert-Butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (0.408 g, 0.680 mmol) was suspended in DCM (1.4 mL). L-Serine methyl ester hydrochloride (0.131 g, 0.842 mmol) was added followed by N,N-diisopropylethylamine (0.350 mL, 2.01 mmol), HOBt·H2O (0.131 g, 0.855 mmol) and EDC·HCl (0.155 g, 0.809 mmol). The mixture was stirred at room temperature for 18 h and water (25 mL) was added. The mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The residue was dissolved in DCM (1.4 mL). Triethylamine (0.115 mL, 0.821 mmol) and acetic anhydride (0.076 mL, 0.804 mmol) were added and the solution was stirred at room temperature for 2 h. Water (25 mL) was added and the mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford O-acetyl-N-(N-(2-(4-((2-((tert-Butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (0.309 g, 61%) as a colorless oil.

[0614] 11H NMR (400 MHz, CDCl3): δ 7.99 (d, J = 7.1 Hz, 1H), 7.43 (d, J = 7.8 Hz, 1H), 7.39 (d, J = 3.0 Hz, 1H), 6.52 (s, 1H), 4.88 (td, J = 9.4, 7.7, 5.5 Hz, 2H), 4.59 (td, J = 7.2, 3.6 Hz, 1H), 4.53–4.44 (m, 1H), 4.31 (dd, J = 11.4, 3.7 Hz, 1H), 4.23–4.16 (m, 1H), 4.03 (dd, J = 17.2, 13.6 Hz, 2H), 3.79–3.69 (m, 1H), 3.76 (s, 3H), 3.42–3.34 (m, 2H), 3.30 (q, J = 5.7, 5.0 Hz, 2H), 3.04 (td, J = 12.4, 3.0 Hz, 2H), 2.31 (tt, J = 11.4, 3.6 Hz, 1H), 2.02 (s, 3H), 2.00–1.90 (m, 2H), 1.88–1.74 (m, 2H), 1.45 (s, 9H), 0.92 (s, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[0615] Methyl 2-(2-(2-(4-((2-((tert-butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (15)

[0616]

[0617] Dissolve O-acetyl-N-(N-(2-(4-((2-((tert-butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (0.309 g, 0.416 mmol) in THF (1 mL). Add tetrabutylammonium fluoride (1 M solution in THF, 0.950 mL, 0.950 mmol), and stir the solution at room temperature for 3 hours. Add water (25 mL), and extract the mixture with ethyl acetate (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Dissolve the residue in DCM (2 mL), and cool to 0 °C. Add triethylamine (0.088 mL, 0.628 mmol) then add methanesulfonyl chloride (0.050 mL, 0.646 mmol). Stir the mixture at 0 °C for 2 hours and add water (25 mL). Extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Dissolve the residue in THF (2 mL), and cool to 0 °C. Add 1,8-diazabicyclo[5.4.0]undec-7-ene (0.094 mL, 0.629 mmol), and stir the solution at 0 °C for 2 hours. Add water (25 mL), and extract the mixture with ethyl acetate (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford methyl 2-(2-(2-(4-((2-((tert-butoxycarbonyl)amino)ethyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (0.046 g, 20%) as a white solid.

[0618] 1 H NMR (400 MHz, CDCl3): δ 9.72 (s, 1H), 8.51 (s, 1H), 7.42 (s, 1H), 6.72 (d, J = 2.1 Hz, 1H), 6.66 (s, 1H), 6.49 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.43 (t, J = 1.9 Hz, 1H), 4.88 (s, 1H), 4.06 (dt, J = 13.0, 3.7 Hz, 2H), 3.89 (s, 3H), 3.43–3.34 (m, 2H), 3.32 (d, J = 7.1 Hz, 2H), 3.08 (ddd, J = 13.0, 11.8, 3.1 Hz, 2H), 2.32 (tt, J = 11.4, 3.7 Hz, 1H), 1.99 (d, J = 3.5 Hz, 2H), 1.90–1.76 (m, 2H), 1.44 (s, 9H).

[0619] Compound 16: Methyl 2-(2-(2-(4-((6-((tert-butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazol-4-ylcarbamoyl)acrylamido)acrylate

[0620] (tert-Butyl (4-cyanobenzyl)carbamate) (16.1)

[0621]

[0622] 4-(Aminomethyl)benzonitrile hydrochloride (2.010 g, 11.9 mmole) was suspended in DCM (24 mL). Di-tert-butyl dicarbonate (2.866 g, 13.1 mmole) was added followed by N,N-diisopropylethylamine (4.20 mL, 24.1 mmole), and the mixture was stirred at room temperature for 3 h. Water (75 mL) was added and the two layers were separated. The aqueous layer was extracted with DCM (2 x 15 mL). The combined organics were dried over sodium sulfate, filtered, and concentrated to afford tert-butyl (4-cyanobenzyl)carbamate (3.311 g) as a white solid.

[0623] 1 H NMR (400 MHz, CDCl3): δ 7.68–7.56 (m, 2H), 7.44–7.34 (m, 2H), 4.97 (s, 1H), 4.37 (d, J = 6.2 Hz, 2H), 1.46 (s, 9H).

[0624] (tert-Butyl (4-thiocarbamoylbenzyl)carbamate) (16.2)

[0625]

[0626] tert-Butyl (4-cyanobenzyl)carbamate (3.311 g, 14.3 mmole) was dissolved in pyridine (14 mL). Triethylamine (2.20 mL, 15.7 mmole) was added followed by ammonium sulfide (40% aqueous solution, 3.00 mL, 17.6 mmole). The solution was heated to 50 °C for 4 h, cooled to room temperature, and concentrated. The residue was dissolved in ethyl acetate (50 mL) and washed successively with 1 N hydrochloric acid (3 x 25 mL) and saturated aqueous sodium chloride (1 x 25 mL). The organics were dried over magnesium sulfate, filtered, and concentrated to afford tert-butyl (4-thiocarbamoylbenzyl)carbamate (3.186 g, 100% from 4-(aminomethyl)benzonitrile hydrochloride) as a yellow solid.

[0627] 11H NMR (400 MHz, DMSO-d6): δ 9.80 (s, 1H), 9.44 (s, 1H), 7.84 (d, J = 8.2 Hz, 2H), 7.44 (t, J = 6.2 Hz, 1H), 7.25 (d, J = 8.2 Hz, 2H), 4.15 (d, J = 6.2 Hz, 2H), 1.39 (s, 9H).

[0628] Ethyl 2-(4-(aminomethyl)phenyl)thiazole-4-carboxylate hydrobromide (16.3)

[0629]

[0630] Dissolve tert-butyl (4-thiocarbamoylbenzyl)carbamate (2.623 g, 9.85 mmole) in ethanol (20 mL). Add ethyl bromopyruvate (1.50 mL, 12.0 mmole), and heat the mixture at 80 °C for 3 h. Cool the mixture to room temperature, and collect the precipitated solid by filtration, wash with a small amount of ethanol, and allow it to air dry to give ethyl 2-(4-(aminomethyl)phenyl)thiazole-4-carboxylate hydrobromide (2.408 g, 71%) as a white solid.

[0631] 1 1H NMR (400 MHz, DMSO-d6): δ 8.62 (s, 1H), 8.42–8.20 (m, 3H), 8.10–8.01 (m, 2H), 7.69–7.60 (m, 2H), 4.35 (q, J = 7.1 Hz, 2H), 4.20–4.09 (m, 2H), 1.34 (t, J = 7.1 Hz, 3H).

[0632] Ethyl 2-(4-((6-((tert-butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carboxylate (16.4)

[0633]

[0634] 6-((tert-Butoxycarbonyl)amino)hexanoic acid (1.795 g, 7.76 mmol) was dissolved in DCM (14 mL). N,N'-Carbonyldiimidazole (1.254 g, 7.73 mmol) was added in portions (gas evolution was observed), and the solution was stirred for 60 minutes. Ethyl 2-(4-(aminomethyl)phenyl)thiazole-4-carboxylate hydrobromide (2.408 g, 7.02 mmol) and N,N-diisopropylethylamine (3.70 mL, 21.2 mmol) were added, and the solution was stirred at room temperature for 20 h. Water (50 mL) was added and the two layers were separated. The aqueous layer was extracted with DCM (2 x 20 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography (50 - 100% ethyl acetate / hexane gradient) to afford ethyl 2-(4-((6-((tert-butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carboxylate (3.060 g, 92%) as a white solid.

[0635] 1 H NMR (400 MHz, CDCl3): δ 8.15 (s, 1H), 8.01–7.92 (m, 2H), 7.40–7.31 (m, 2H), 5.97 (s, 1H), 4.56 (s, 1H), 4.48 (d, J = 5.9 Hz, 2H), 4.45 (q, J = 7.1 Hz, 2H), 3.10 (q, J = 6.7 Hz, 2H), 2.25 (t, J = 7.5 Hz, 2H), 1.76–1.64 (m, 2H), 1.50 (ddd, J = 14.3, 7.4, 3.9 Hz, 2H), 1.45–1.40 (m, 12H), 1.40–1.31 (m, 2H).

[0636] 2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carboxylic acid (16.5)

[0637]

[0638] Using the procedure described in Example 1.3, ethyl 2-(4-((6-((tert-butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carboxylate (3.060 g, 6.43 mmol) was converted to 2-(4-((6-((tert-butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carboxylic acid (2.756 g, 96%) as a white solid.

[0639] 11H NMR (400 MHz, DMSO-d6): δ 8.48 (s, 1H), 8.39 (t, J = 6.0 Hz, 1H), 7.94 (d, J = 8.3 Hz, 2H), 7.43–7.33 (m, 2H), 6.76 (t, J = 5.8 Hz, 1H), 4.32 (d, J = 5.9 Hz, 2H), 2.90 (q, J = 6.6 Hz, 2H), 2.15 (t, J = 7.4 Hz, 2H), 1.53 (p, J = 7.5 Hz, 2H), 1.37 (s, 11H), 1.24 (td, J = 8.4, 4.3 Hz, 2H).

[0640] N-(2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (16.6)

[0641]

[0642] Using the procedure described in Example 12.3, 2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carboxylic acid (2.756 g, 6.16 mmole) was converted to N-(2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (3.291 g, 77%) as a colorless oil.

[0643] 1 1H NMR (400 MHz, CDCl3): δ 8.21 (d, J = 8.7 Hz, 1H), 8.07 (s, 1H), 7.96–7.87 (m, 2H), 7.40–7.31 (m, 2H), 6.01 (s, 1H), 4.90–4.80 (m, 1H), 4.57 (s, 1H), 4.49 (d, J = 5.8 Hz, 2H), 4.21 (dd, J = 10.0, 2.7 Hz, 1H), 3.95 (dd, J = 10.1, 3.4 Hz, 1H), 3.79 (s, 3H), 3.11 (q, J = 6.7 Hz, 2H), 2.26 (t, J = 7.5 Hz, 2H), 1.78–1.66 (m, 2H), 1.56–1.47 (m, 2H), 1.43 (s, 9H), 1.41–1.33 (m, 2H), 0.92 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[0644] N-(2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (16.7)

[0645]

[0646] Using the procedure described in Example 4.3, N-(2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (3.291 g, 4.96 mmol) was converted to white solid N-(2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (3.097 g, 96%).

[0647] 1 H NMR (400 MHz, DMSO-d6): δ 8.42 - 8.36 (m, 1H), 8.37 (s, 1H), 8.18 (d, J = 8.6 Hz, 1H), 8.00–7.90 (m, 2H), 7.42–7.35 (m, 2H), 6.77 (d, J = 6.1 Hz, 1H), 4.59 (dt, J = 8.6, 3.5 Hz, 1H), 4.33 (d, J = 5.9 Hz, 2H), 4.12 (dd, J = 10.3, 3.4 Hz, 1H), 3.96 (dd, J = 10.4, 3.7 Hz, 1H), 2.89 (q, J = 6.6 Hz, 2H), 2.15 (t, J = 7.4 Hz, 2H), 1.53 (p, J = 7.5 Hz, 2H), 1.37 (s, 11H), 1.31–1.20 (m, 2H), 0.88 (s, 9H), 0.06 (s, 3H), 0.04 (s, 3H).

[0648] N-(2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (16.8)

[0649]

[0650] Dissolve N-(2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (3.097 g, 4.77 mmol) in DCM (9 mL). Add L-serine methyl ester hydrochloride (0.898 g, 5.77 mmol) and then add N,N-diisopropylethylamine (1.70 mL, 9.76 mmol), HOBt·H2O (0.881 g, 5.75 mmol), and EDC·HCl (1.101 g, 5.74 mmol). Stir the mixture at room temperature for 18 h. Add water (50 mL) and separate the two layers. Extract the aqueous layer with DCM (2 x 15 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography (80 - 100% ethyl acetate / hexane gradient) to afford N-(2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine methyl ester (2.354 g, 66%) as a white solid.

[0651] 1 H NMR (400 MHz, CDCl3): δ 8.24 (d, J = 7.1 Hz, 1H), 8.06 (s, 1H), 7.89–7.84 (m, 2H), 7.52 (d, J = 7.5 Hz, 1H), 7.35–7.29 (m, 2H), 6.15–6.02 (m, 1H), 4.74–4.63 (m, 2H), 4.61 (d, J = 13.7 Hz, 1H), 4.48 (d, J = 6.1 Hz, 2H), 4.19 (dd, J = 9.8, 4.1 Hz, 1H), 4.05–3.95 (m, 2H), 3.88–3.82 (m, 1H), 3.78 (d, J = 9.3 Hz, 4H), 3.11 (q, J = 6.7 Hz, 3H), 2.26 (t, J = 7.6 Hz, 2H), 1.75–1.66 (m, 3H), 1.55–1.46 (m, 2H), 1.43 (s, 10H), 1.41–1.32 (m, 2H), 0.94 (d, J = 1.1 Hz, 9H), 0.14 (s, 3H), 0.12 (s, 3H).

[0652] (2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carbonyl)-L-seryl-L-serine methyl ester (16.9)

[0653]

[0654] Dissolve N-(2-(4-((6-((tert-butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl-L-serine ester (2.354 g, 3.14 mmole) in THF (6 mL). Add tetrabutylammonium fluoride (1 M solution in THF, 3.50 mL, 3.50 mmole) and stir the solution at room temperature for 2 hours. Add water (50 mL) and collect the precipitated solid by filtration, wash with water and allow it to air dry to afford (2-(4-((6-((tert-butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carbonyl)-L-seryl-L-serine methyl ester (1.790 g, 90%) as a white solid.

[0655] 1 H NMR (400 MHz, DMSO-d6): δ 8.49–8.41 (m, 2H), 8.38 (d, J = 2.7 Hz, 1H), 8.31 (dd, J = 8.1, 2.6 Hz, 1H), 8.08–7.99 (m, 2H), 7.49–7.40 (m, 2H), 6.80 (d, J = 6.0 Hz, 1H), 4.68 (dt, J = 8.2, 5.2 Hz, 1H), 4.46 (dt, J = 7.8, 4.6 Hz, 1H), 4.37 (d, J = 6.0 Hz, 2H), 3.86–3.73 (m, 3H), 3.68 (d, J = 4.2 Hz, 4H), 2.93 (q, J = 6.6 Hz, 2H), 2.19 (t, J = 7.4 Hz, 2H), 1.57 (p, J = 7.5 Hz, 2H), 1.41 (s, 11H), 1.33–1.22 (m, 2H).

[0656] Methyl 2-(2-(2-(4-((6-((tert-butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (16)

[0657]

[0658] (2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carbonyl)-L-seryl-L-serine methyl ester (0.306 g, 0.481 mmol) was dissolved in DMF (2 mL) and cooled to 0 °C. Triethylamine (0.200 mL, 1.43 mmol) was added and then methanesulfonyl chloride (0.110 mL, 1.42 mmol) was added. The mixture was stirred at 0 °C for 60 minutes and water (25 mL) was added. The mixture was extracted with ethyl acetate (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The residue was suspended in THF and cooled to 0 °C. 1,8-Diazabicyclo[5.4.0]undec-7-ene (0.210 mL, 1.40 mmol) was added and the mixture was stirred at 0 °C for 60 minutes. Water (25 mL) was added and the mixture was extracted with ethyl acetate (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography (80 - 100% ethyl acetate / hexane gradient) to afford a white solid. The solid was triturated with ethyl acetate and collected by filtration to afford methyl 2-(2-(2-(4-((6-((tert-Butoxycarbonyl)amino)hexanamido)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (0.014 g, 4.9%).

[0659] 1 H NMR (400 MHz, DMSO-d6): δ 9.97 (s, 1H), 9.95 (s, 1H), 8.48 (s, 1H), 8.38 (m, 1H), 8.02–7.91 (m, 2H), 7.46–7.36 (m, 2H), 6.76 (s, 1H), 6.51 (d, J = 1.3 Hz, 1H), 5.87 (d, J = 1.4 Hz, 1H), 5.87 (s, 1H), 5.84 (s, 1H), 4.32 (d, J = 5.9 Hz, 2H), 3.75 (s, 3H), 2.89 (q, J = 6.6 Hz, 2H), 2.15 (t, J = 7.5 Hz, 2H), 1.53 (p, J = 7.5 Hz, 2H), 1.36 (s, 11H), 1.24 (q, J = 8.4, 7.6 Hz, 2H).

[0660] Compound 17: Methyl 2-(2-(2-morpholinothiazol-4-ylcarbamoyl)acrylamido)acrylate

[0661] Ethyl 2-morpholinothiazole-4-carboxylate (17.1)

[0662]

[0663] Ethyl 2-bromothiazole-4-carboxylate (1.009 g, 4.27 mmol) was dissolved in N,N-dimethylacetamide (8 mL). Morpholine (0.410 mL, 4.69 mmol) and triethylamine (0.710 mL, 5.07 mmol) were added, and the mixture was heated to 80 °C for 24 h and then cooled to room temperature. Water (50 mL) was added, and the mixture was extracted with ethyl acetate (3 x 15 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography (20-40% ethyl acetate / hexane gradient) to afford ethyl 2-morpholinothiazole-4-carboxylate (0.721 g, 70%) as a pale yellow solid.

[0664] 1 H NMR (400 MHz, CDCl3): δ 7.48 (s, 1H), 4.36 (q, J = 7.1 Hz, 2H), 3.86–3.77 (m, 4H), 3.57–3.47 (m, 4H), 1.37 (t, J = 7.2 Hz, 3H).

[0665] 2-Morpholinothiazole-4-carboxylic acid (17.2)

[0666]

[0667] Using the procedure described in Example 1.3, ethyl 2-morpholinothiazole-4-carboxylate (0.721 g, 2.96 mmol) was converted to 2-morpholinothiazole-4-carboxylic acid (0.341 g, 54%) as a white solid.

[0668] 1 H NMR (400 MHz, DMSO-d6): δ 12.62 (s, 1H), 7.67 (s, 1H), 3.74–3.64 (m, 4H), 3.39 (ddd, J = 6.3, 4.9, 3.5 Hz, 4H).

[0669] O-(tert-Butyldimethylsilyl)-N-(2-morpholinothiazole-4-carbonyl)-L-serine methyl ester (17.3)

[0670]

[0671] Using the procedure described in Example 12.3, 2-morpholinothiazole-4-carboxylic acid (0.341 g, 1.59 mmol) was converted to O-(tert-butyldimethylsilyl)-N-(2-morpholinothiazole-4-carbonyl)-L-serine methyl ester (0.494 g, 72%) as a colorless oil.

[0672] 11H NMR (400 MHz, CDCl3): δ 7.95 (d, J = 8.8 Hz, 1H), 7.43 (s, 1H), 4.79 (ddd, J = 8.8, 3.4, 2.6 Hz, 1H), 4.20–4.13 (m, 1H), 3.85–3.79 (m, 6H), 3.76 (s, 3H), 3.56–3.50 (m, 2H), 3.48 (q, J = 4.9 Hz, 4H), 0.88 (s, 9H), 0.04 (s, 3H), 0.03 (s, 3H).

[0673] O-(tert-Butyldimethylsilyl)-N-(2-morpholinothiazole-4-carbonyl)-L-serine (17.4)

[0674]

[0675] Using the procedure described in Example 4.3, O-(tert-butyldimethylsilyl)-N-(2-morpholinothiazole-4-carbonyl)-L-serine methyl ester (0.494 g, 1.15 mmole) was converted to O-(tert-butyldimethylsilyl)-N-(2-morpholinothiazole-4-carbonyl)-L-serine (0.396 g, 83%) as a colorless gel.

[0676] 1 1H NMR (400 MHz, DMSO-d6): δ 7.87 (d, J = 8.6 Hz, 1H), 7.56 (d, J = 6.1 Hz, 1H), 4.53 (dt, J = 8.7, 3.3 Hz, 1H), 4.13–4.08 (m, 1H), 3.91 (dd, J = 10.3, 3.6 Hz, 1H), 3.81–3.71 (m, 4H), 3.51–3.41 (m, 4H), 0.89 (d, J = 1.9 Hz, 9H), 0.07 (s, 3H), 0.06 (s, 3H).

[0677] O-Acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-morpholinothiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (17.5)

[0678]

[0679] Using the procedure described in Example 15.6, O-(tert-butyldimethylsilyl)-N-(2-morpholinothiazole-4-carbonyl)-L-serine (0.396 g, 0.953 mmole) was converted to O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-morpholinothiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.339 g, 64%) as a colorless oil.

[0680] 1 1H NMR (400 MHz, CDCl3): δ 7.99 (d, J = 7.1 Hz, 1H), 7.43 (d, J = 2.2 Hz, 2H), 4.91–4.82 (m, 1H), 4.63–4.54 (m, 1H), 4.53–4.41 (m, 1H), 4.35 (ddd, J = 26.4, 11.4, 3.7 Hz, 1H), 4.18 (ddd, J = 9.8, 3.7, 0.9 Hz, 1H), 3.87–3.79 (m, 5H), 3.76 (s, 3H), 3.53–3.44 (m, 4H), 2.03 (s, 3H), 0.92 (d, J = 1.0 Hz, 9H), 0.15 (s, 3H), 0.12 (s, 3H).

[0681] Methyl 2-(2-(2-morpholinothiazole-4-carboxamido)acrylamido)acrylate (17)

[0682]

[0683] Using the procedure described for Compound 15, O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-morpholinothiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.339 g, 0.607 mmole) was converted to methyl 2-(2-(2-morpholinothiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.093 g, 42%).

[0684] 1 1H NMR (400 MHz, CDCl3): δ 9.74 (s, 1H), 8.51 (s, 1H), 7.47 (s, 1H), 6.73 (d, J = 2.2 Hz, 1H), 6.65 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.44 (t, J = 1.9 Hz, 1H), 3.89 (s, 3H), 3.86–3.77 (m, 4H), 3.57–3.46 (m, 4H).

[0685] Compound 18: tert-Butyl 4-(4-((3-((3-methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en- 2-yl)carbamoyl)thiazol-2-yl)piperazine-1-carboxylate

[0686] Ethyl 2-(4-(tert-butoxycarbonyl)piperazin-1-yl)thiazole-4-carboxylate (18.1)

[0687]

[0688] Ethyl 2-bromothiazole-4-carboxylate (1.001 g, 4.24 mmol) was dissolved in N,N-dimethylacetamide (8 mL). Piperazine-1-carboxylic acid tert-butyl ester (1.182 g, 6.35 mmol) was added and then trimethylamine (0.720 mL, 5.14 mmol) was added, and the mixture was heated at 80 °C for 3 days and then cooled to room temperature. Water (50 mL) was added, and the mixture was extracted with ethyl acetate (3 x 15 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography (10-40% ethyl acetate / hexane gradient) to afford ethyl 2-(4-(tert-butoxycarbonyl)piperazin-1-yl)thiazole-4-carboxylate (1.325 g, 92%) as a pale yellow solid. 1 H NMR (400 MHz, CDCl3): δ 7.47 (s, 1H), 4.36 (q, J = 7.1 Hz, 2H), 3.59–3.47 (m, 8H), 1.48 (s, 9H), 1.37 (t, J = 7.1 Hz, 3H).

[0689] 2-(4-(tert-Butoxycarbonyl)piperazin-1-yl)thiazole-4-carboxylic acid (18.2)

[0690]

[0691] Using the procedure described in Example 1.3, ethyl 2-(4-(tert-butoxycarbonyl)piperazin-1-yl)thiazole-4-carboxylate (1.325 g, 3.88 mmol) was converted to 2-(4-(tert-butoxycarbonyl)piperazin-1-yl)thiazole-4-carboxylic acid (1.187 g, 98%) as a white solid.

[0692] 1 H NMR (400 MHz, DMSO-d6): δ 12.63 (s, 1H), 7.66 (s, 1H), 3.52–3.36 (m, 8H), 1.42 (s, 9H).

[0693] (S)-4-(4-((3-((tert-Butyldimethylsilyl)oxy)-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)piperazine-1-carboxylic acid tert-butyl ester (18.3)

[0694]

[0695] Using the procedure described in Example 15.3, 2-(4-(tert-Butoxycarbonyl)piperazin-1-yl)thiazole-4-carboxylic acid (1.187 g, 3.79 mmole) was converted to tert-butyl ((S)-4-(4-((3-((tert-butyldimethylsilyl)oxy)-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)piperazine-1-carboxylate (1.920 g, 96%) as a white solid.

[0696] 1 H NMR (400 MHz, CDCl3): δ 7.94 (d, J = 8.7 Hz, 1H), 7.42 (s, 1H), 4.78 (ddd, J = 8.8, 3.4, 2.6 Hz, 1H), 4.19–4.14 (m, 1H), 3.89 (dd, J = 10.0, 3.4 Hz, 1H), 3.76 (s, 3H), 3.56 (t, J = 5.1 Hz, 4H), 3.48 (q, J = 5.3, 4.5 Hz, 4H), 1.49 (s, 9H), 0.88 (s, 9H), 0.05 (s, 3H), 0.03 (s, 3H).

[0697] N-(2-(4-(tert-Butoxycarbonyl)piperazin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (18.4)

[0698]

[0699] Using the procedure described in Example 4.3, tert-butyl ((S)-4-(4-((3-((tert-butyldimethylsilyl)oxy)-1-methoxy-1-oxopropan-2-yl)carbamoyl)thiazol-2-yl)piperazine-1-carboxylate (1.920 g, 3.63 mmole) was converted to N-(2-(4-(tert-Butoxycarbonyl)piperazin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (1.922 g) as a white solid.

[0700] 1 H NMR (400 MHz, DMSO-d6): δ 7.87 (d, J = 8.6 Hz, 1H), 7.55 (d, J = 6.8 Hz, 1H), 4.53 (dt, J = 8.7, 3.3 Hz, 1H), 4.15–4.09 (m, 1H), 3.91 (dd, J = 10.3, 3.6 Hz, 1H), 3.52 (s, 8H), 1.47 (s, 9H), 0.89 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[0701] tert-Butyl 4-(4-(((6S,9S)-9-(methoxycarbonyl)-2,2,3,3-tetramethyl-7,12-dioxo-4,11-dioxa-8-aza-3-silatridecane-6-yl)carbamoyl)thiazol-2-yl)piperazine-1-carboxylate (18.5)

[0702]

[0703] Using the procedure described in Example 15.6, N-(2-(4-(tert-butoxycarbonyl)piperazin-1-yl)thiazol-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine (1.922 g, 3.73 mmole) was converted to tert-butyl 4-(4-(((6S,9S)-9-(methoxycarbonyl)-2,2,3,3-tetramethyl-7,12-dioxo-4,11-dioxa-8-aza-3-silatridecane-6-yl)carbamoyl)thiazol-2-yl)piperazine-1-carboxylate (1.481 g, 60%) as a colorless oil.

[0704] 1 H NMR (400 MHz, CDCl3): δ 7.99 (d, J = 7.0 Hz, 1H), 7.48–7.39 (m, 2H), 4.88 (dt, J = 7.6, 3.7 Hz, 1H), 4.58 (td, J = 7.2, 3.7 Hz, 1H), 4.52–4.45 (m, 1H), 4.32 (dd, J = 11.4, 3.6 Hz, 1H), 4.18 (dd, J = 9.8, 3.7 Hz, 1H), 3.76 (d, J = 2.0 Hz, 3H), 3.73 (d, J = 9.7 Hz, 1H), 3.56 (dq, J = 5.6, 2.6 Hz, 4H), 3.52–3.43 (m, 4H), 2.05 (s, 3H), 1.49 (s, 9H), 0.93 (s, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[0705] tert-Butyl 4-(4-((3-((3-methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)piperazine-1-carboxylate (18)

[0706]

[0707] Using the procedure described for Compound 15, tert-butyl 4-(4-(((6S,9S)-9-(methoxycarbonyl)-2,2,3,3-tetramethyl-7,12-dioxo-4,11-dioxa-8-aza-3-silatridecane-6-yl)carbamoyl)thiazol-2-yl)piperazine-1-carboxylate (1.481 g, 2.25 mmole) was converted to tert-butyl 4-(4-((3-((3-methoxy-3-oxoprop-1-en-2-yl)amino)-3-oxoprop-1-en-2-yl)carbamoyl)thiazol-2-yl)piperazine-1-carboxylate (0.206 g, 20%) as a white solid.

[0708] 1 H NMR (400 MHz, CDCl3): δ 9.73 (s, 1H), 8.52 (s, 1H), 7.46 (s, 1H), 6.72 (d, J = 2.1 Hz, 1H), 6.66 (s, 1H), 6.01 (d, J = 1.3 Hz, 1H), 5.44 (t, J = 1.9 Hz, 1H), 3.89 (s, 3H), 3.58 (dd, J = 6.6, 3.5 Hz, 4H), 3.51 (dt, J = 7.4, 3.5 Hz, 4H), 1.49 (s, 9H).

[0709] Compound 19: Methyl 2-(2-(2-(4-(6-azidohexanamido)piperidin-1-yl)thiazol-4-ylcarbamoyl)acry lamido)acrylate

[0710] Ethyl 2-(4-(6-bromohexanamido)piperidin-1-yl)thiazole-4-carboxylate (19.1)

[0711]

[0712] 6-Bromohexanoic acid (1.212 g, 6.21 mmole) was dissolved in DCM (5.5 mL), and DMF (2 drops) was added. Oxalyl chloride (0.540 mL, 6.19 mmole) was added dropwise (gas evolution was observed), and the solution was stirred at room temperature for 3 h and then concentrated.

[0713] In a separate flask, 2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylic acid ethyl ester (1.995 g, 5.61 mmole) was dissolved in DCM (11 mL). HCl (4 M solution in 1,4-dioxane, 5.60 mL, 22.4 mmole) was added and the mixture was stirred at room temperature for 3 h and concentrated. The residue was dissolved in DCM (11 mL) and cooled to 0 °C. N,N-Diisopropylethylamine (2.00 mL, 11.5 mmole) was added, then a solution of the acyl chloride generated above in DCM (2 mL) was added slowly. The resulting mixture was stirred at 0 °C for 15 min, then at room temperature for 18 h. Water (50 mL) was added and the two layers were separated. The aqueous layer was extracted with DCM (3 x 15 mL). The combined organics were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography (10-40% ethyl acetate / hexane gradient) to afford ethyl 2-(4-(6-bromohexanamido)piperidin-1-yl)thiazole-4-carboxylate (1.287 g, 53%) as a white solid.

[0714] 1 H NMR (400 MHz, CDCl3): δ 7.44 (s, 1H), 5.34 (d, J = 7.9 Hz, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.08–3.97 (m, 3H), 3.41 (t, J = 6.7 Hz, 2H), 3.17 (ddd, J = 13.3, 11.8, 2.9 Hz, 2H), 2.18 (t, J = 7.4 Hz, 2H), 2.10–1.99 (m, 2H), 1.88 (dq, J = 7.9, 6.8 Hz, 2H), 1.74–1.62 (m, 2H), 1.57–1.42 (m, 4H), 1.37 (t, J = 7.1 Hz, 3H).

[0715] Ethyl 2-(4-(6-azidohexanamido)piperidin-1-yl)thiazole-4-carboxylate (19.2)

[0716]

[0717] Ethyl 2-(4-(6-bromohexanamido)piperidin-1-yl)thiazole-4-carboxylate (1.287 g, 2.98 mmole) was dissolved in DMF (6 mL). Sodium azide (0.233 g, 3.58 mmole) was added and the mixture was heated to 80 °C for 18 h and then cooled to room temperature. The mixture was diluted with ethyl acetate (25 mL) and washed with water (3 x 25 mL). The organic layer was dried over magnesium sulfate, filtered and concentrated to afford ethyl 2-(4-(6-azidohexanamido)piperidin-1-yl)thiazole-4-carboxylate (1.127 g, 96%) as a pale yellow solid.

[0718] 1 H NMR (400 MHz, CDCl3): δ 7.44 (s, 1H), 5.51 (d, J = 7.6 Hz, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.01 (dddd, J = 11.2, 7.1, 4.4, 2.2 Hz, 3H), 3.28 (t, J = 6.8 Hz, 2H), 3.16 (ddd, J = 13.4, 11.8, 2.9 Hz, 2H), 2.18 (t, J = 7.5 Hz, 2H), 2.04 (d, J = 7.3 Hz, 2H), 1.73–1.57 (m, 4H), 1.57–1.46 (m, 2H), 1.46–1.39 (m, 2H), 1.37 (t, J = 7.1 Hz, 3H).

[0719] N-(2-(4-(6-azidohexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (19.3)

[0720]

[0721] Ethyl 2-(4-(6-azidohexanamido)piperidin-1-yl)thiazole-4-carboxylate (1.127 g, 2.86 mmol) was dissolved in 4 / 1 / 1 THF / methanol / water (5.7 mL). Lithium hydroxide monohydrate (0.240 g, 5.72 mmol) was added and the mixture was stirred at room temperature for 2 h. Water (40 mL) was added and the solution was treated with 1 N hydrochloric acid to pH = 4. The mixture was extracted with ethyl acetate (3 x 15 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The residue was suspended in DCM (5.7 mL) and L-serine methyl ester hydrochloride (0.535 g, 3.44 mmol) was added. N,N-Diisopropylethylamine (1.00 mL, 5.74 mmol), HOBt.H2O (0.530 g, 3.46 mmol) and EDC.HCl (0.664 g, 3.46 mmol) were added and the mixture was stirred at room temperature for 18 h. Water (25 mL) was added and the mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The residue was dissolved in DCM (5.7 mL). Imidazole (0.215 g, 3.16 mmol) and tert-butyldimethylchlorosilane (0.477 g, 3.16 mmol) were added and the mixture was stirred at room temperature for 3 h. Water (25 mL) was added and the mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography (50 - 90% ethyl acetate / hexane gradient) to afford N-(2-(4-(6-azidohexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (1.561 g, 94%) as a thick colorless oil.

[0722] 1 H NMR (400 MHz, CDCl3): δ 7.95 (d, J = 8.8 Hz, 1H), 7.38 (s, 1H), 5.44 (d, J = 7.9 Hz, 1H), 4.84–4.73 (m, 1H), 4.19–4.14 (m, 1H), 4.07–3.98 (m, 2H), 3.98–3.90 (m, 1H), 3.88 (dd, J = 10.0, 3.4 Hz, 1H), 3.76 (s, 3H), 3.28 (t, J = 6.8 Hz, 2H), 3.21–3.08 (m, 2H), 2.19 (t, J = 7.5 Hz, 2H), 2.03–1.96 (m, 2H), 1.74–1.57 (m, 4H), 1.57–1.47 (m, 2H), 1.47–1.37 (m, 2H), 0.88 (s, 9H), 0.05 (s, 3H), 0.03 (s, 3H).

[0723] O-Acetyl-N-(N-(2-(4-(6-azidohexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (19.4)

[0724]

[0725] Using the procedure described in Example 15.6, N-(2-(4-(6-azidohexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (1.561 g, 2.68 mmole) was converted to O-acetyl-N-(N-(2-(4-(6-azidohexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (1.312 g, 69%) as a thick pale yellow oil.

[0726] 1 H NMR (400 MHz, CDCl3): δ 7.98 (d, J = 7.1 Hz, 1H), 7.43 (d, J = 7.8 Hz, 1H), 7.40 (d, J = 2.6 Hz, 1H), 5.38 (d, J = 7.9 Hz, 1H), 4.87 (dq, J = 8.0, 4.0 Hz, 1H), 4.58 (td, J = 7.2, 3.6 Hz, 1H), 4.52–4.43 (m, 1H), 4.31 (dd, J = 11.4, 3.7 Hz, 1H), 4.18 (ddd, J = 9.9, 3.7, 1.4 Hz, 1H), 4.08–3.91 (m, 3H), 3.76 (d, J = 2.1 Hz, 3H), 3.75–3.69 (m, 1H), 3.28 (t, J = 6.8 Hz, 2H), 3.21–3.07 (m, 2H), 2.19 (t, J = 7.5 Hz, 2H), 2.01 (s, 3H), 1.73–1.57 (m, 6H), 1.51 (ddd, J = 12.6, 9.1, 5.3 Hz, 2H), 1.46–1.38 (m, 2H), 0.92 (s, 9H), 0.14 (s, 3H), 0.12 (s, 3H).

[0727] Methyl 2-(2-(2-(4-(6-azidohexanamido)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (19)

[0728]

[0729] Using the procedure described for Compound 18, O-acetyl-N-(N-(2-(4-(6-azidohexanamido)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (1.312 g, 1.85 mmol) was converted to methyl 2-(2-(2-(4-(6-azidohexanamido)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (0.481 g, 50%) as a white solid.

[0730] 1 H NMR (400 MHz, CDCl3): δ 9.71 (s, 1H), 8.51 (s, 1H), 7.43 (s, 1H), 6.72 (d, J = 2.1 Hz, 1H), 6.65 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.44 (t, J = 1.9 Hz, 1H), 5.36 (d, J = 7.9 Hz, 1H), 4.10–3.96 (m, 3H), 3.89 (s, 3H), 3.28 (t, J = 6.8 Hz, 2H), 3.17 (ddd, J = 13.3, 11.8, 2.9 Hz, 2H), 2.19 (t, J = 7.5 Hz, 2H), 2.11–2.00 (m, 2H), 1.74–1.60 (m, 4H), 1.56–1.46 (m, 2H), 1.46–1.36 (m, 2H).

[0731] Compound 20: (S)-Methyl 2-(2-(2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazol-4-ylcarbamoyl) acrylamido)acrylate

[0732] (S)-Ethyl 2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (20.1)

[0733]

[0734] Ethyl 2-bromothiazole-4-carboxylate (2.003 g, 8.48 mmol) was dissolved in DMA (9 mL). (S)-tert-Butyl piperidin-3-ylcarbamate (1.873 g, 9.35 mmol) was added followed by trimethylamine (1.45 mL, 10.3 mmol) and the mixture was heated to 80 °C for 24 h, then cooled to room temperature and diluted with ethyl acetate (50 mL). The mixture was washed with water (3 x 25 mL), dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography (30–60% ethyl acetate / hexane gradient) to afford (S)-ethyl 2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (2.606 g, 86%) as a pale yellow solid. 11H NMR (400 MHz, CDCl3): δ 7.44 (s, 1H), 4.71 (s, 1H), 4.35 (q, J = 7.1 Hz, 2H), 3.80 (s, 1H), 3.71 (d, J = 11.5 Hz, 1H), 3.61 (s, 1H), 3.45 (s, 1H), 3.34–3.20 (m, 1H), 1.91 (ddd, J = 12.4, 7.8, 3.6 Hz, 1H), 1.86–1.76 (m, 1H), 1.76–1.64 (m, 1H), 1.60 (s, 1H), 1.51 (s, 9H), 1.37 (t, J = 7.1 Hz, 3H).

[0735] N-(2-((S)-3-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (20.2)

[0736]

[0737] Using the procedure described for Example 22.3, ethyl (S)-2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (0.750 g, 2.11 mmole) was converted to N-(2-((S)-3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (1.074 g, 94%) as a colorless oil.

[0738] 1 1H NMR (400 MHz, CDCl3): δ 7.94 (d, J = 8.8 Hz, 1H), 7.38 (s, 1H), 4.79 (ddd, J = 8.8, 3.4, 2.6 Hz, 1H), 4.75–4.65 (m, 1H), 4.19–4.15 (m, 1H), 3.88 (dd, J = 10.0, 3.4 Hz, 1H), 3.81 (s, 1H), 3.76 (s, 3H), 3.65 (d, J = 12.7 Hz, 1H), 3.55 (d, J = 18.5 Hz, 1H), 3.45 (s, 1H), 3.35–3.20 (m, 1H), 1.98–1.76 (m, 2H), 1.71 (dq, J = 7.8, 3.8 Hz, 1H), 1.61 (s, 1H), 1.45 (s, 9H), 0.88 (s, 9H), 0.06 (s, 3H), 0.03 (s, 3H).

[0739] O-Acetyl-N-(N-(2-((S)-3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (20.3)

[0740]

[0741] Using the procedure described in Example 15.6, N-(2-((S)-3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (1.074 g, 1.98 mmole) was converted into O-acetyl-N-(N-(2-((S)-3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (1.154 g, 87%) as a thick colorless gel. 1 H NMR (400 MHz, CDCl3): δ 7.97 (d, J = 7.2 Hz, 1H), 7.43 (d, J = 7.7 Hz, 1H), 7.40 (d, J = 2.4 Hz, 1H), 4.87 (dt, J = 7.7, 3.8 Hz, 1H), 4.69 (s, 1H), 4.59 (td, J = 7.1, 3.6 Hz, 1H), 4.52–4.44 (m, 1H), 4.31 (dd, J = 11.4, 3.7 Hz, 1H), 4.18 (dd, J = 9.8, 3.7 Hz, 1H), 3.76 (d, J = 2.8 Hz, 3H), 3.75–3.70 (m, 1H), 3.70–3.52 (m, 2H), 3.44 (s, 1H), 3.36–3.16 (m, 1H), 2.03 (d, J = 2.1 Hz, 3H), 1.96–1.86 (m, 1H), 1.87–1.76 (m, 1H), 1.76–1.65 (m, 1H), 1.65 - 1.59 (m, 1H), 1.45 (s, 9H), 0.92 (s, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[0742] (S)-2-(2-(2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)methyl acrylate (20)

[0743]

[0744] Using the procedure described for Compound 15, O-acetyl-N-(N-(2-((S)-3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (1.154 g, 1.72 mmol) was converted to methyl (S)-2-(2-(2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (0.372 g, 45%) as a white solid.

[0745] 1 H NMR (400 MHz, CDCl3): δ 9.71 (s, 1H), 8.50 (s, 1H), 7.43 (s, 1H), 6.71 (d, J = 2.1 Hz, 1H), 6.66 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.43 (t, J = 1.8 Hz, 1H), 4.70 (s, 1H), 3.89 (s, 3H), 3.82 (s, 1H), 3.74–3.53 (m, 2H), 3.47 (s, 1H), 3.30 (s, 1H), 1.97–1.78 (m, 2H), 1.72 (qt, J = 8.1, 3.7 Hz, 1H), 1.62 (s, 1H), 1.45 (s, 9H).

[0746] Compound 21: Methyl 2-(2-(2-(4-((ethoxycarbonyl)(methyl)amino)piperidin-1-yl)thiazol-4-ylcarbam oyl)acrylamido)acrylate

[0747] tert-Butyl 4-((ethoxycarbonyl)(methyl)amino)piperidine-1-carboxylate (21.1)

[0748]

[0749] tert-Butyl 4-(methylamino)piperidine-1-carboxylate (0.752 g, 3.51 mmol) was dissolved in DCM (7 mL) and cooled to 0 °C. N,N-Diisopropylethylamine (0.670 mL, 3.85 mmol) was added, followed by dropwise addition of ethyl chloroformate (0.370 mL, 3.87 mmol). The mixture was stirred at 0 °C for 60 minutes. Water (50 mL) was added and the mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography (20–60% ethyl acetate / hexane gradient) to afford tert-Butyl 4-((ethoxycarbonyl)(methyl)amino)piperidine-1-carboxylate (0.959 g, 95%) as a colorless oil. 11H NMR (400 MHz, CDCl3): δ 4.27 - 4.13 (m, 3H), 4.14 (q, J = 7.1 Hz, 2H), 2.82 - 2.69 (m, 2H), 2.76 (s, 3H), 1.60 (qd, J = 11.7, 5.8 Hz, 4H), 1.44 (s, 9H), 1.27 (t, J = 7.1 Hz, 3H).

[0750] Ethyl 2-(4-((ethoxycarbonyl)(methyl)amino)piperidin-1-yl)thiazole-4-carboxylate (21.2)

[0751]

[0752] Dissolve tert-butyl 4-((ethoxycarbonyl)(methyl)amino)piperidine-1-carboxylate (0.959 g, 3.35 mmole) in DCM (7 mL). Add HCl (4 M solution in 1,4-dioxane, 3.40 mL, 13.6 mmole), and stir the mixture at room temperature for 3 h, then concentrate. Dissolve the residue in DMA (4 mL). Add ethyl 2-bromothiazole-4-carboxylate (0.837 g, 3.55 mmole) then add N,N-diisopropylethylamine (0.940 mL, 5.40 mmole), and heat the mixture at 80 °C for 18 h, then cool to room temperature. Add ethyl acetate (25 mL), and wash the mixture with water (3 x 25 mL). Dry the organic layer over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography (10 - 60% ethyl acetate / hexane gradient) to afford ethyl 2-(4-((ethoxycarbonyl)(methyl)amino)piperidin-1-yl)thiazole-4-carboxylate (0.322 g, 28%) as a yellow oil.

[0753] 1 1H NMR (400 MHz, CDCl3): δ 7.44 (s, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.20 – 4.09 (m, 5H), 3.18 – 3.05 (m, 2H), 2.77 (s, 3H), 1.78 (qd, J = 8.7, 6.8, 3.7 Hz, 4H), 1.37 (t, J = 7.1 Hz, 3H), 1.28 (t, J = 7.1 Hz, 3H).

[0754] O-(tert-Butyldimethylsilyl)-N-(2-(4-((ethoxycarbonyl)(methyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (21.3)

[0755]

[0756] Using the procedure described in Example 19.3, ethyl 2-(4-((ethoxycarbonyl)(methyl)amino)piperidin-1-yl)thiazole-4-carboxylate (0.322 g, 0.943 mmole) was converted to O-(tert-butyldimethylsilyl)-N-(2-(4-((ethoxycarbonyl)(methyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.300 g, 60%) as a thick colorless oil.

[0757] 1 H NMR (400 MHz, CDCl3): δ 7.95 (d, J = 8.8 Hz, 1H), 7.38 (s, 1H), 4.78 (ddd, J = 8.8, 3.3, 2.6 Hz, 1H), 4.21–4.02 (m, 6H), 3.89 (dd, J = 10.0, 3.4 Hz, 1H), 3.76 (s, 3H), 3.17–3.03 (m, 2H), 2.79 (s, 3H), 1.76 (d, J = 4.0 Hz, 4H), 1.33–1.25 (m, 3H), 0.88 (s, 9H), 0.05 (s, 3H), 0.03 (s, 3H).

[0758] O-Acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((ethoxycarbonyl)(methyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (21.4)

[0759]

[0760] Using the procedure described in Example 15.6, O-(tert-butyldimethylsilyl)-N-(2-(4-((ethoxycarbonyl)(methyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.300 g, 0.567 mmole) was converted to O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((ethoxycarbonyl)(methyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.297 g, 80%) as a white solid. 11H NMR (400 MHz, CDCl3): δ 7.98 (d, J = 7.1 Hz, 1H), 7.43 (d, J = 7.5 Hz, 1H), 7.39 (d, J = 2.5 Hz, 1H), 4.87 (dt, J = 7.7, 3.8 Hz, 1H), 4.58 (td, J = 7.2, 3.6 Hz, 1H), 4.51–4.45 (m, 1H), 4.31 (dd, J = 11.4, 3.7 Hz, 1H), 4.22–4.14 (m, 3H), 4.14–4.04 (m, 3H), 3.76 (d, J = 2.2 Hz, 3H), 3.75–3.70 (m, 1H), 3.11 (d, J = 12.5 Hz, 2H), 2.78 (s, 3H), 2.02 (d, J = 2.7 Hz, 3H), 1.77 (s, 4H), 1.29 (t, J = 7.7 Hz, 3H), 0.92 (s, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[0761] Methyl 2-(2-(2-(4-((ethoxycarbonyl)(methyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (21)

[0762]

[0763] Using the procedure described for compound 15, O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((ethoxycarbonyl)(methyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.297 g, 0.451 mmole) was converted to methyl 2-(2-(2-(4-((ethoxycarbonyl)(methyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.090 g, 43%).

[0764] 1 1H NMR (400 MHz, CDCl3): δ 9.72 (s, 1H), 8.51 (s, 1H), 7.42 (s, 1H), 6.72 (d, J = 2.1 Hz, 1H), 6.66 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.44 (t, J = 1.8 Hz, 1H), 4.28 (s, 1H), 4.20–4.08 (m, 4H), 3.89 (s, 3H), 3.18–3.04 (m, 2H), 2.79 (s, 3H), 1.79 (s, 4H), 1.28 (t, J = 7.1 Hz, 3H).

[0765] Compound 22: Methyl 2-(2-(2-(4-(((ethoxycarbonyl)amino)methyl)piperidin-1-yl)thiazol-4-ylcarbam oyl)acrylamido)acrylate

[0766] tert-Butyl 4-(((ethoxycarbonyl)amino)methyl)piperidine-1-carboxylate (22.1)

[0767]

[0768] Dissolve tert-butyl 4-(aminomethyl)piperidine-1-carboxylate (0.754 g, 3.52 mmol) in DCM (7 mL) and cool to 0 °C. Add N,N-diisopropylethylamine (0.730 mL, 4.19 mmol), then add ethyl chloroformate (0.370 mL, 3.87 mmol) dropwise. Stir the mixture at 0 °C for 60 minutes. Add water (25 mL) and separate the two layers. Extract the aqueous layer with DCM (2 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography (20 - 40% ethyl acetate / hexane gradient) to afford tert-butyl 4-(((ethoxycarbonyl)amino)methyl)piperidine-1-carboxylate (0.997 g, 99%) as a thick colorless oil.

[0769] 1 H NMR (400 MHz, CDCl3): δ 4.77 (s, 1H), 4.19–4.03 (m, 4H), 3.07 (t, J = 6.4 Hz, 2H), 2.68 (t, J = 12.9 Hz, 2H), 1.71–1.63 (m, 2H), 1.44 (s, 9H), 1.25 (dt, J = 9.0, 7.1 Hz, 4H), 1.17–1.03 (m, 2H).

[0770] Ethyl 2-(4-(((ethoxycarbonyl)amino)methyl)piperidin-1-yl)thiazole-4-carboxylate (22.2)

[0771]

[0772] Dissolve tert-butyl 4-(((ethoxycarbonyl)amino)methyl)piperidine-1-carboxylate (0.997 g, 3.48 mmole) in DCM (7 mL). Add HCl (4 M solution in 1,4-dioxane, 3.50 mL, 14.0 mmole), and stir the mixture at room temperature for 3 hours, then concentrate. Dissolve the residue in DMA (4 mL). Add ethyl 2-bromothiazole-4-carboxylate (0.905 g, 3.83 mmole) and N,N-diisopropylethylamine (1.20 mL, 6.89 mmole), and heat the mixture to 80 °C for 18 hours, and cool to room temperature, then dilute with ethyl acetate (25 mL). Wash the mixture with water (3 x 25 mL), and dry the organic matter over magnesium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography (10 - 70% ethyl acetate / hexane gradient) to afford ethyl 2-(4-(((ethoxycarbonyl)amino)methyl)piperidin-1-yl)thiazole-4-carboxylate (0.600 g, 50%) as a yellow solid.

[0773] 1 H NMR (400 MHz, CDCl3): δ 7.42 (s, 1H), 4.77 (s, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.18–4.02 (m, 4H), 3.11 (t, J = 6.4 Hz, 2H), 3.01 (td, J = 12.7, 2.8 Hz, 2H), 1.86–1.77 (m, 2H), 1.73 (d, J = 6.8 Hz, 1H), 1.37 (t, J = 7.1 Hz, 3H), 1.35–1.29 (m, 2H), 1.25 (td, J = 7.1, 5.9 Hz, 3H).

[0774] O-(tert-Butyldimethylsilyl)-N-(2-(4-(((ethoxycarbonyl)amino)methyl)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (22.3)

[0775]

[0776] Using the procedure described in Example 19.3, convert ethyl 2-(4-(((ethoxycarbonyl)amino)methyl)piperidin-1-yl)thiazole-4-carboxylate (0.600 mL, 1.76 mmole) into O-(tert-butyldimethylsilyl)-N-(2-(4-(((ethoxycarbonyl)amino)methyl)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.897 g, 96%) as a thick colorless gel.

[0777] 11H NMR (400 MHz, CDCl3): δ 7.96 (d, J = 8.8 Hz, 1H), 7.36 (s, 1H), 4.78 (dt, J = 8.8, 3.0 Hz, 2H), 4.20–4.08 (m, 3H), 4.02 (dd, J = 11.7, 5.3 Hz, 2H), 3.88 (dd, J = 10.0, 3.4 Hz, 1H), 3.76 (s, 3H), 3.12 (t, J = 6.4 Hz, 2H), 2.99 (tdd, J = 12.5, 6.0, 2.6 Hz, 2H), 1.81 (s, 2H), 1.34 (tt, J = 11.5, 5.2 Hz, 2H), 1.26 (td, J = 7.1, 2.9 Hz, 3H), 0.88 (s, 9H), 0.05 (s, 3H), 0.03 (s, 3H).

[0778] O-Acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-(((ethoxycarbonyl)amino)methyl)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (22.4)

[0779]

[0780] Using the procedure described in Example 15.6, O-(tert-butyldimethylsilyl)-N-(2-(4-(((ethoxycarbonyl)amino)methyl)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.897 g, 1.70 mmole) was converted to O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-(((ethoxycarbonyl)amino)methyl)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.921 g, 82%) as a colorless oil. 11H NMR (400 MHz, CDCl3): δ 7.99 (d, J = 7.1 Hz, 1H), 7.43 (d, J = 7.8 Hz, 1H), 7.37 (d, J = 2.8 Hz, 1H), 4.87 (dq, J = 8.0, 3.9 Hz, 1H), 4.77 (s, 1H), 4.58 (d dd, J = 7.2, 5.9, 3.6 Hz, 1H), 4.47 (dt, J = 11.3, 4.2 Hz, 1H), 4.31 (dd, J = 11.4, 3.7 Hz, 1H), 4.19 (ddd, J = 9.8, 3.6, 2.0 Hz, 1H), 4.12 (q, J = 7.1 Hz, 2H), 4.01 (d, J = 13.0 Hz, 2H), 3.76 (d, J = 2.3 Hz, 3H), 3.75–3.70 (m, 1H), 3.12 (t, J = 6.4 Hz, 2H), 2.99 (tt, J = 12.8, 3.0 Hz, 2H), 2.02 (d, J = 2.4 Hz, 3H), 1.82 (s, 2H), 1.32 (d, J = 12.2 Hz, 2H), 1.26 (td, J = 7.1, 3.5 Hz, 3H), 0.92 (s, 9H), 0.14 (s, 3H), 0.12 (s, 3H).

[0781] Methyl 2-(2-(2-(4-(((ethoxycarbonyl)amino)methyl)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (22)

[0782]

[0783] Using the procedure described for compound 15, O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-(((ethoxycarbonyl)amino)methyl)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.921 g, 1.40 mmol) was converted to methyl 2-(2-(2-(4-(((ethoxycarbonyl)amino)methyl)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (0.310 g, 48%) as a white solid.

[0784] 11H NMR (400 MHz, CDCl3): δ 9.78–9.67 (m, 1H), 8.51 (s, 1H), 7.41 (s, 1H), 6.71 (d, J = 2.1 Hz, 1H), 6.66 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.43 (t, J = 1.9 Hz, 1H), 4.76 (s, 1H), 4.12 (q, J = 7.1 Hz, 2H), 4.09–3.98 (m, 2H), 3.89 (s, 3H), 3.12 (t, J = 6.4 Hz, 2H), 3.02 (td, J = 12.7, 2.8 Hz, 2H), 1.85 (d, J = 3.5 Hz, 2H), 1.35 (td, J = 12.3, 4.4 Hz, 2H), 1.25 (t, J = 7.1 Hz, 3H).

[0785] Compound 23: (R)-Methyl 2-(2-(2-(3-((ethoxycarbonyl)amino)pyrrolidin-1-yl)thiazol-4-ylcarbam oyl)acrylamido)acrylate

[0786] (R)-tert-Butyl 3-((ethoxycarbonyl)amino)pyrrolidine-1-carboxylate (23.1)

[0787]

[0788] (R)-tert-Butyl 3-aminopyrrolidine-1-carboxylate (1.016 g, 5.45 mmol) was dissolved in DCM (11 mL) and cooled to 0 °C. N,N-Diisopropylethylamine (1.15 mL, 6.60 mmol) and ethyl chloroformate (0.560 mL, 5.86 mmol) were then added. The mixture was stirred at 0 °C for 90 minutes and water (50 mL) was added. The two layers were separated and the aqueous layer was extracted with DCM (2 x 15 mL). The combined organic matter was dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography (30–60% ethyl acetate / hexane) to afford (R)-tert-Butyl 3-((ethoxycarbonyl)amino)pyrrolidine-1-carboxylate (1.597 g) as a colorless oil. 1 1H NMR (400 MHz, CDCl3): δ 4.84 (s, 1H), 4.23 (d, J = 8.2 Hz, 1H), 4.12 (q, J = 7.1 Hz, 2H), 3.60 (dd, J = 11.4, 6.2 Hz, 1H), 3.50–3.34 (m, 2H), 3.20 (d, J = 25.0 Hz, 1H), 2.13 (dtd, J = 13.2, 7.5, 5.9 Hz, 1H), 1.90–1.75 (m, 1H), 1.43 (s, 9H), 1.25 (td, J = 7.2, 5.6 Hz, 3H).

[0789] (R)-Ethyl 2-(3-((ethoxycarbonyl)amino)pyrrolidin-1-yl)thiazole-4-carboxylate (23.2)

[0790]

[0791] Dissolve tert-butyl (R)-3-((ethoxycarbonyl)amino)pyrrolidine-1-carboxylate (1.597 g, 6.18 mmol) in DCM (12 mL). Add HCl (4 M solution in 1,4-dioxane, 6.20 mL, 24.8 mmol), and stir the mixture at room temperature for 75 minutes and concentrate. Dissolve the residue in DMA (6 mL), and add ethyl 2-bromothiazole-4-carboxylate (1.613 g, 6.83 mmol) and N,N-diisopropylethylamine (2.15 mL, 12.3 mmol). Heat the mixture to 80 °C for 3 days, and cool to room temperature. Add ethyl acetate (25 mL), and wash the mixture with water (3 x 25 mL). Dry the organic matter over magnesium sulfate, filter and concentrate. Purify the residue by silica gel chromatography (30 - 70% ethyl acetate / hexane gradient) to afford (R)-ethyl 2-(3-((ethoxycarbonyl)amino)pyrrolidin-1-yl)thiazole-4-carboxylate (1.105 g, 57%) as a white solid.

[0792] 1 1H NMR (400 MHz, CDCl3): δ 7.40 (s, 1H), 4.83 (s, 1H), 4.47–4.39 (m, 1H), 4.36 (q, J = 7.1 Hz, 2H), 4.13 (q, J = 7.0 Hz, 2H), 3.79 (dd, J = 10.7, 6.0 Hz, 1H), 3.61 (qt, J = 10.0, 6.4 Hz, 2H), 3.43 (dd, J = 10.6, 4.2 Hz, 1H), 2.33 (dddd, J = 13.0, 8.1, 7.2, 6.0 Hz, 1H), 2.09–1.96 (m, 1H), 1.37 (t, J = 7.1 Hz, 3H), 1.25 (t, J = 7.1 Hz, 3H).

[0793] O-(tert-Butyldimethylsilyl)-N-(2-((R)-3-((ethoxycarbonyl)amino)pyrrolidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (23.3)

[0794]

[0795] Using the procedure described in Example 19.3, ethyl (R)-2-(3-((ethoxycarbonyl)amino)pyrrolidin-1-yl)thiazole-4-carboxylate (1.105 g, 3.53 mmole) was converted to O-(tert-butyldimethylsilyl)-N-(2-((R)-3-((ethoxycarbonyl)amino)pyrrolidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.859 g, 49%) as a colorless oil.

[0796] 1 H NMR (400 MHz, CDCl3): δ 7.99 (d, J = 8.8 Hz, 1H), 7.34 (s, 1H), 4.90 (s, 1H), 4.84–4.75 (m, 1H), 4.43 (s, 1H), 4.19–4.12 (m, 3H), 3.89 (dd, J = 10.0, 3.4 Hz, 1H), 3.76 (s, 3H), 3.75–3.69 (m, 1H), 3.59–3.51 (m, 2H), 3.38 (dd, J = 10.8, 4.2 Hz, 1H), 2.41–2.27 (m, 1H), 2.07 - 1.98 (m, 1H), 1.26 (t, J = 7.1 Hz, 3H), 0.89 (s, 9H), 0.06 (s, 3H), 0.03 (s, 3H).

[0797] O-Acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-((R)-3-((ethoxycarbonyl)amino)pyrrolidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (23.4)

[0798]

[0799] Using the procedure described in Example 15.6, O-(tert-butyldimethylsilyl)-N-(2-((R)-3-((ethoxycarbonyl)amino)pyrrolidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.859 g, 1.72 mmole) was converted to O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-((R)-3-((ethoxycarbonyl)amino)pyrrolidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.753 g, 70%) as a pale yellow oil.

[0800] 11H NMR (400 MHz, CDCl3): δ 8.02 (d, J = 7.2 Hz, 1H), 7.44 (d, J = 7.8 Hz, 1H), 7.35 (d, J = 2.4 Hz, 1H), 4.87 (dq, J = 7.7, 3.9 Hz, 2H), 4.59 (ddd, J = 7.2, 6.0, 3.7 Hz, 1H), 4.51–4.44 (m, 1H), 4.43 (d, J = 7.5 Hz, 1H), 4.31 (dd, J = 11.4, 3.7 Hz, 1H), 4.18 (dd, J = 9.8, 3.7 Hz, 1H), 4.12 (q, J = 7.2 Hz, 3H), 3.76 (d, J = 2.5 Hz, 4H), 3.75–3.70 (m, 1H), 3.56 (ddt, J = 7.8, 5.8, 2.7 Hz, 2H), 3.38 (dd, J = 10.7, 4.2 Hz, 1H), 2.41–2.27 (m, 1H), 2.06 - 1.99 (m, 1H), 2.02 (s, 3H), 1.26 (td, J = 7.1, 2.2 Hz, 3H), 0.93 (d, J = 1.4 Hz, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[0801] (R)-Methyl 2-(2-(2-(3-((ethoxycarbonyl)amino)pyrrolidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (23)

[0802]

[0803] Using the procedure described for compound 15, O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-((R)-3-((ethoxycarbonyl)amino)pyrrolidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.753 g, 1.20 mmole) was converted to (R)-methyl 2-(2-(2-(3-((ethoxycarbonyl)amino)pyrrolidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (0.224 g, 43%) as a white solid.

[0804] 11H NMR (400 MHz, CDCl3): δ 9.77 (s, 1H), 8.50 (s, 1H), 7.38 (s, 1H), 6.71 (d, J = 2.1 Hz, 1H), 6.67 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.43 (t, J = 1.9 Hz, 1H), 4.85 (s, 1H), 4.44 (s, 1H), 4.13 (p, J = 7.0 Hz, 2H), 3.89 (s, 3H), 3.79 (dd, J = 10.7, 6.1 Hz, 1H), 3.69–3.52 (m, 2H), 3.41 (dd, J = 10.6, 4.3 Hz, 1H), 2.35 (dddd, J = 12.9, 8.1, 7.1, 6.0 Hz, 1H), 2.04 (d, J = 5.0 Hz, 1H), 1.32–1.20 (m, 3H).

[0805] Compound 24: Methyl 2-(2-(2-(4-(2-methoxyethoxyphenyl)thiazol-4-ylcarbamoyl)acrylamido) acrylate

[0806] 4-(2-Methoxyethoxy)benzonitrile (24.1)

[0807]

[0808] Dissolve 2-methoxyethanol (1.008 g, 13.2 mmol) in DMF (13 mL). Add sodium hydride (60% dispersion in mineral oil, 0.578 g, 14.5 mmol) portionwise (gas evolution was observed). Stir the mixture at room temperature for 30 minutes and add 4-fluorobenzonitrile (1.670 g, 13.8 mmol). Heat the mixture to 80 °C for 2 1 / 2 h and cool to room temperature. Add ethyl acetate (25 mL) and wash the mixture with water (3 x 25 mL). Dry the organic layer over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography (5–55% ethyl acetate / hexane gradient) to afford 4-(2-methoxyethoxy)benzonitrile (1.406 g, 60%) as a colorless solid.

[0809] 1 1H NMR (400 MHz, CDCl3): δ 7.62–7.55 (m, 2H), 7.02–6.94 (m, 2H), 4.20–4.13 (m, 2H), 3.80–3.73 (m, 2H), 3.45 (s, 3H).

[0810] 4-(2-Methoxyethoxy)thiobenzamide (24.2)

[0811]

[0812] 4-(2-Methoxyethoxy)benzonitrile (1.406 g, 7.93 mmol) was dissolved in pyridine (8 mL). Triethylamine (1.20 mL, 8.56 mmol) was added and then ammonium sulfide (40% aqueous solution, 1.60 mL, 9.36 mmol) was added. The mixture was heated to 50 °C for 20 h and cooled to room temperature, then concentrated. The residue was treated with diethyl ether (20 mL), and the solid was collected by filtration to afford 4-(2-methoxyethoxy)thiobenzamide as a yellow solid (1.070 g, 64%).

[0813] 1 H NMR (400 MHz, DMSO-d6): δ 9.64 (s, 1H), 9.32 (s, 1H), 8.01–7.89 (m, 2H), 7.01–6.91 (m, 2H), 4.21–4.11 (m, 2H), 3.72–3.62 (m, 2H), 3.31 (s, 3H).

[0814] Ethyl 2-(4-(2-methoxyethoxy)phenyl)thiazole-4-carboxylate (24.3)

[0815]

[0816] 4-(2-Methoxyethoxy)thiobenzamide (1.070 g, 5.06 mmol) was dissolved in ethanol (10 mL). Ethyl bromopyruvate (0.770 mL, 6.14 mmol) was added, and the mixture was heated to 80 °C for 3 h and then cooled to room temperature, which caused a solid to precipitate from the solution. The solid was collected by filtration, washed with cold ethanol, and allowed to air dry to afford ethyl 2-(4-(2-methoxyethoxy)phenyl)thiazole-4-carboxylate as a yellow solid (0.931 g, 60%).

[0817] 1 H NMR (400 MHz, CDCl3): δ 8.09 (s, 1H), 7.98–7.90 (m, 2H), 7.02–6.94 (m, 2H), 4.44 (q, J = 7.1 Hz, 2H), 4.22–4.14 (m, 2H), 3.82–3.74 (m, 2H), 3.46 (s, 3H), 1.43 (t, J = 7.1 Hz, 3H).

[0818] O-(tert-Butyldimethylsilyl)-N-(2-(4-(2-methoxyethoxy)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (24.4)

[0819]

[0820] Using the procedure described in Example 19.3, ethyl 2-(4-(2-methoxyethoxy)phenyl)thiazole-4-carboxylate (0.931 g, 3.03 mmol) was converted to O-(tert-butyldimethylsilyl)-N-(2-(4-(2-methoxyethoxy)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (1.481 g, 99%) as a colorless oil.

[0821] 1 H NMR (400 MHz, CDCl3): δ 8.23 (d, J = 8.7 Hz, 1H), 8.03 (s, 1H), 7.94–7.85 (m, 2H), 7.04–6.95 (m, 2H), 4.85 (dt, J = 8.7, 3.1 Hz, 1H), 4.24–4.16 (m, 3H), 3.95 (dd, J = 10.0, 3.4 Hz, 1H), 3.83–3.74 (m, 2H), 3.74 (s, 3H), 3.47 (s, 3H), 0.92 (s, 9H), 0.07 (s, 3H), 0.06 (s, 3H).

[0822] O-Acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-(2-methoxyethoxy)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (24.5)

[0823]

[0824] Using the procedure described in Example 15.6, O-(tert-butyldimethylsilyl)-N-(2-(4-(2-methoxyethoxy)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.701 g, 1.42 mmol) was converted to O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-(2-methoxyethoxy)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.644 g, 73%) as a colorless oil.

[0825] 11H NMR (400 MHz, CDCl3): δ 8.27 (d, J = 7.3 Hz, 1H), 8.04 (d, J = 2.8 Hz, 1H), 7.95–7.85 (m, 2H), 7.46 (d, J = 7.8 Hz, 1H), 6.99 (dd, J = 8.3, 1.5 Hz, 2H), 4.89 (tt, J = 6.5, 3.8 Hz, 1H), 4.66 (ddd, J = 8.9, 6.5, 3.7 Hz, 1H), 4.54–4.46 (m, 1H), 4.33 (dd, J = 11.4, 3.6 Hz, 1H), 4.23 (dd, J = 9.8, 3.7 Hz, 1H), 4.21–4.17 (m, 2H), 3.82–3.78 (m, 2H), 3.78 - 3.74 (m, 1H), 3.76 (s, 3H), 3.47 (s, 3H), 2.01 (s, 3H), 0.95 (s, 9H), 0.15 (s, 3H), 0.14 (s, 3H).

[0826] Methyl 2-(2-(2-(4-(2-methoxyethoxy)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (24)

[0827]

[0828] Using the procedure described for compound 15, O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-(2-methoxyethoxy)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.644 g, 1.03 mmole) was converted to methyl 2-(2-(2-(4-(2-methoxyethoxy)phenyl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.203 g, 46%).

[0829] 1 1H NMR (400 MHz, CDCl3): δ 10.01 (s, 1H), 8.55 (s, 1H), 8.08 (s, 1H), 7.99–7.90 (m, 2H), 7.06–6.96 (m, 2H), 6.78 (d, J = 2.2 Hz, 1H), 6.71 (s, 1H), 6.03 (d, J = 1.3 Hz, 1H), 5.49 (t, J = 1.9 Hz, 1H), 4.25–4.13 (m, 2H), 3.90 (s, 3H), 3.85–3.74 (m, 2H), 3.48 (s, 3H).

[0830] Compound 25: Methyl 2-(2-(2-(4-(6-azidohexanamido)phenyl)thiazol-4-ylcarbamoyl)acrylamido) acrylate

[0831] (4-Thiocarbamoylphenyl)carbamic acid tert-butyl ester (25.1)

[0832]

[0833] Dissolve (4-cyanophenyl)carbamic acid tert-butyl ester (1.002 g, 4.59 mmole) in pyridine (5 mL). Add triethylamine (0.710 mL, 5.07 mmole) and ammonium sulfide (40% aqueous solution, 0.940 mL, 5.50 mmole), and heat the mixture at 50 °C for 18 h, then cool to room temperature and concentrate. Suspend the residue in ethyl acetate (25 mL), and wash the mixture with 1 N hydrochloric acid (2 x 25 mL). Dry the organic matter over magnesium sulfate, filter and concentrate to afford (4-thiocarbamoylphenyl)carbamic acid tert-butyl ester (1.102 g, 95%) as a yellow solid.

[0834] 1 H NMR (400 MHz, DMSO-d6): δ 9.64 (d, J = 4.7 Hz, 2H), 9.30 (s, 1H), 7.92–7.83 (m, 2H), 7.52–7.42 (m, 2H), 1.48 (s, 9H).

[0835] Ethyl 2-(4-(6-bromohexanamido)phenyl)thiazole-4-carboxylate (25.2)

[0836]

[0837] Dissolve (4-thiocarbamoylphenyl)carbamic acid tert-butyl ester (1.102 g, 4.37 mmole) in ethanol (9 mL). Add ethyl bromopyruvate (0.610 mL, 4.86 mmole), and heat the mixture at 80 °C for 2 h, then cool to room temperature and concentrate to afford ethyl 2-(4-aminophenyl)thiazole-4-carboxylate hydrobromide (1.591 g) as an orange solid.

[0838] 6-Bromohexanoic acid (1.373 g, 7.04 mmol) was dissolved in DCM (13 mL). DMF (2 drops) was added, and then oxalyl chloride (0.620 mL, 7.11 mmol; gas evolution was observed) was added slowly. The solution was stirred at room temperature for 2 h and concentrated. The residue was dissolved in DCM (2 mL) and slowly added to a cold (0 °C) mixture of ethyl 2-(4-aminophenyl)thiazole-4-carboxylate hydrobromide (1.591 g) and N,N-diisopropylethylamine (2.25 mL, 12.9 mmol) in DCM (13 mL). The resulting mixture was stirred at 0 °C for 90 min and poured into 1 N hydrochloric acid (25 mL) and water (25 mL). The two layers were separated, and the aqueous layer was extracted with DCM (2 x 15 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography (10 - 70% ethyl acetate / hexane gradient) to afford ethyl 2-(4-(6-bromohexanamido)phenyl)thiazole-4-carboxylate (1.211 g, 65%) as a yellow solid.

[0839] 1 H NMR (400 MHz, CDCl3): δ 8.12 (s, 1H), 8.00–7.91 (m, 2H), 7.68 (d, J = 8.7 Hz, 2H), 7.64 (s, 1H), 4.45 (q, J = 7.1 Hz, 2H), 3.42 (t, J = 6.7 Hz, 2H), 2.42 (t, J = 7.4 Hz, 2H), 1.90 (dq, J = 10.4, 6.8 Hz, 2H), 1.77 (tt, J = 8.1, 6.3 Hz, 2H), 1.53 (ddt, J = 12.2, 6.5, 3.9 Hz, 2H), 1.43 (t, J = 7.1 Hz, 3H).

[0840] Ethyl 2-(4-(6-azidohexanamido)phenyl)thiazole-4-carboxylate (25.3)

[0841]

[0842] Ethyl 2-(4-(6-bromohexanamido)phenyl)thiazole-4-carboxylate (1.211 g, 2.85 mmol) was dissolved in DMF (6 mL). Sodium azide (0.224 g, 3.45 mmol) was added, and the mixture was heated to 80 °C for 3 h. The mixture was cooled to room temperature and diluted with ethyl acetate (25 mL). The mixture was washed with water (3 x 25 mL) and saturated aqueous sodium chloride (1 x 25 mL), then dried over magnesium sulfate, filtered, and concentrated to afford ethyl 2-(4-(6-azidohexanamido)phenyl)thiazole-4-carboxylate (0.899 g, 81%) as a yellow solid.

[0843] 1 1H NMR (400 MHz, CDCl3): δ 8.12 (s, 1H), 8.00–7.93 (m, 2H), 7.66 (d, J = 8.6 Hz, 2H), 7.55 (s, 1H), 4.45 (q, J = 7.1 Hz, 2H), 3.29 (t, J = 6.8 Hz, 2H), 2.41 (t, J = 7.4 Hz, 2H), 1.77 (tt, J = 8.1, 6.4 Hz, 2H), 1.71–1.58 (m, 2H), 1.51–1.46 (m, 2H), 1.43 (t, J = 7.1 Hz, 3H).

[0844] N-(2-(4-(6-Azidohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (25.4)

[0845]

[0846] Using the procedure described for Example 19.3, ethyl 2-(4-(6-azidohexanamido)phenyl)thiazole-4-carboxylate (0.899 g, 2.32 mmole) was converted to N-(2-(4-(6-azidohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester as a thick orange oil (0.615 g, 46%).

[0847] 1 1H NMR (400 MHz, CDCl3): δ 8.22 (d, J = 8.7 Hz, 1H), 8.05 (s, 1H), 7.94–7.85 (m, 2H), 7.62 (d, J = 8.6 Hz, 2H), 7.50 (s, 1H), 4.85 (dt, J = 8.7, 3.1 Hz, 1H), 4.22 (dd, J = 10.1, 2.7 Hz, 1H), 3.95 (dd, J = 10.1, 3.4 Hz, 1H), 3.79 (s, 3H), 3.30 (t, J = 6.8 Hz, 2H), 2.41 (t, J = 7.4 Hz, 2H), 1.84–1.72 (m, 2H), 1.72–1.59 (m, 2H), 1.54–1.43 (m, 2H), 0.92 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[0848] O-Acetyl-N-(N-(2-(4-(6-azidohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (25.5)

[0849]

[0850] Using the procedure described in Example 15.6, N-(2-(4-(6-azidohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (0.615 g, 1.07 mmol) was converted to O-acetyl-N-(N-(2-(4-(6-azidohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester as a pale yellow oil (0.517 g, 69%).

[0851] 1 H NMR (400 MHz, CDCl3): δ 8.25 (dd, J = 7.3, 4.4 Hz, 1H), 8.07 (d, J = 3.4 Hz, 1H), 7.96–7.88 (m, 2H), 7.63 (d, J = 8.3 Hz, 2H), 7.47 (d, J = 7.7 Hz, 1H), 7.42 (d, J = 7.6 Hz, 1H), 4.95–4.85 (m, 1H), 4.67 (td, J = 7.2, 3.7 Hz, 1H), 4.55–4.45 (m, 1H), 4.34 (dd, J = 11.4, 3.6 Hz, 1H), 4.22 (dt, J = 9.9, 3.8 Hz, 1H), 3.81 (dd, J = 9.8, 7.4 Hz, 1H), 3.77 (s, 3H), 3.31 (t, J = 6.8 Hz, 2H), 2.42 (t, J = 7.4 Hz, 2H), 2.01 (s, 3H), 1.85–1.74 (m, 2H), 1.71–1.64 (m, 2H), 1.56–1.43 (m, 2H), 0.96 (s, 9H), 0.16 (s, 3H), 0.15 (s, 3H).

[0852] Methyl 2-(2-(2-(4-(6-azidohexanamido)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (25)

[0853]

[0854] Using the procedure described for Compound 15, O-acetyl-N-(N-(2-(4-(6-azidohexanamido)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (0.517 g, 0.734 mmol) was converted to methyl 2-(2-(2-(4-(6-azidohexanamido)phenyl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.093 g, 25%).

[0855] 1 1H NMR (400 MHz, CDCl3): δ 10.00 (s, 1H), 8.55 (s, 1H), 8.12 (s, 1H), 8.03–7.92 (m, 2H), 7.64 (d, J = 8.3 Hz, 2H), 7.29 (s, 1H), 6.78 (d, J = 2.2 Hz, 1H), 6.71 (s, 1H), 6.04 (d, J = 1.3 Hz, 1H), 5.50 (t, J = 1.9 Hz, 1H), 3.91 (s, 3H), 3.31 (t, J = 6.8 Hz, 2H), 2.42 (t, J = 7.4 Hz, 2H), 1.80 (tt, J = 9.5, 6.5 Hz, 2H), 1.73–1.60 (m, 2H), 1.54–1.43 (m, 2H).

[0856] Compound 26: Methyl 2-(2-(2-(4-((((2-methoxyethoxy)carbonyl)amino)methyl)phenyl)thiazol-4-ylcarbam oyl)acrylamido)acrylate

[0857] 2-Methoxyethyl 1H-imidazole-1-carboxylate (26.1)

[0858]

[0859] Following the literature procedure (RSC Advances, 2014, 4(25), 13012 - 13017) (27), 2-methoxyethanol (1.05 mL, 13.3 mmole) was dissolved in THF (26 mL). N,N'-Carbonyldiimidazole (2.560 g, 15.8 mmole) was added and the solution was stirred at room temperature for 20 h. Water (100 mL) was added and the mixture was extracted with ethyl acetate (3 x 25 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated to afford 2-methoxyethyl 1H-imidazole-1-carboxylate (2.757 g) as a colorless oil.

[0860] 1 1H NMR (400 MHz, CDCl3): δ 8.20–8.12 (m, 1H), 7.45 (t, J = 1.5 Hz, 1H), 7.07 (dd, J = 1.7, 0.9 Hz, 1H), 4.60–4.52 (m, 2H), 3.76–3.69 (m, 2H), 3.42 (s, 3H).

[0861] 2-Methoxyethyl (4-cyanobenzyl)carbamate (26.2)

[0862]

[0863] 2-Methoxyethyl 1H-imidazole-1-carboxylate (1.261 g, 7.41 mmol) was dissolved in DMF (14 mL). 4-(Aminomethyl)benzonitrile hydrochloride (1.027 g, 7.77 mmol) and N,N-diisopropylethylamine (1.90 mL, 10.9 mmol) were added, and the solution was heated to 70 °C for 2 1 / 2 days, then cooled to room temperature. Ethyl acetate (40 mL) was added, and the mixture was washed with water (3 x 25 mL). The organic matter was dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography (40 - 80% ethyl acetate / hexane gradient) to afford 2-methoxyethyl (4-cyanobenzyl)carbamate (0.888 g, 51%) as a yellow solid.

[0864] 1 1H NMR (400 MHz, CDCl3): δ 7.67–7.58 (m, 2H), 7.40 (dq, J = 7.4, 0.8 Hz, 2H), 5.23 (s, 1H), 4.43 (d, J = 6.3 Hz, 2H), 4.31–4.24 (m, 2H), 3.64–3.53 (m, 2H), 3.40 (s, 3H).

[0865] 2-Methoxyethyl (4-thiocarbamoylbenzyl)carbamate (26.3)

[0866]

[0867] 2-Methoxyethyl (4-cyanobenzyl)carbamate (0.888 g, 3.79 mmol) was dissolved in pyridine (4 mL). Triethylamine (0.590 mL, 4.21 mmol) and ammonium sulfide (40% aqueous solution, 0.780 mL, 4.57 mmol) were added, and the mixture was warmed to 50 °C for 5 h, then cooled to room temperature and concentrated. The residue was suspended in ethyl acetate (25 mL). The mixture was washed successively with 1 N hydrochloric acid (2 x 15 mL) and water (1 x 15 mL). The aqueous layer was extracted with ethyl acetate (1 x 10 mL). The combined organic matter was dried over magnesium sulfate, filtered, and concentrated to afford 2-methoxyethyl (4-thiocarbamoylbenzyl)carbamate (0.932 g, 92%) as a yellow solid.

[0868] 11H NMR (400 MHz, DMSO-d6): δ 9.81 (s, 1H), 9.44 (s, 1H), 7.87–7.82 (m, 2H), 7.82–7.75 (m, 1H), 7.27 (d, J = 8.3 Hz, 2H), 4.20 (d, J = 6.2 Hz, 2H), 4.12–4.04 (m, 2H), 3.53–3.44 (m, 2H), 3.25 (s, 3H).

[0869] Ethyl 2-(4-((((2-methoxyethoxy)carbonyl)amino)methyl)phenyl)thiazole-4-carboxylate (26.4)

[0870]

[0871] Dissolve 2-methoxyethyl (4-thiocarbamoylbenzyl)carbamate (0.932 g, 3.47 mmole) in ethanol (7 mL). Add ethyl bromopyruvate (0.480 mL, 3.83 mmole), and heat the mixture at 80 °C for 2 1 / 2 h. Cool the mixture to room temperature and concentrate. Suspend the residue in ethyl acetate (25 mL), and wash with water (1 x 25 mL), saturated aqueous sodium bicarbonate (1 x 25 mL), water (1 x 25 mL), and saturated aqueous sodium chloride (1 x 25 mL). Dry the organic layer over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography (40–80% ethyl acetate / hexane gradient) to afford ethyl 2-(4-((((2-methoxyethoxy)carbonyl)amino)methyl)phenyl)thiazole-4-carboxylate (0.887 g, 70%) as a white solid.

[0872] 1 1H NMR (400 MHz, CDCl3): δ 8.15 (s, 1H), 8.03–7.92 (m, 2H), 7.39–7.33 (m, 2H), 5.16 (s, 1H), 4.49–4.39 (m, 4H), 4.32–4.23 (m, 2H), 3.64–3.56 (m, 2H), 3.40 (s, 3H), 1.43 (t, J = 7.1 Hz, 3H).

[0873] O-(tert-Butyldimethylsilyl)-N-(2-(4-((((2-methoxyethoxy)carbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (26.5)

[0874]

[0875] Using the procedure described in Example 19.3, ethyl 2-(4-((((2-methoxyethoxy)carbonyl)amino)methyl)phenyl)thiazole-4-carboxylate (0.887 g, 2.43 mmole) was converted to O-(tert-butyldimethylsilyl)-N-(2-(4-((((2-methoxyethoxy)carbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (1.202 g, 90%) as a thick colorless oil.

[0876] 1 H NMR (400 MHz, CDCl3): δ 8.22 (d, J = 8.7 Hz, 1H), 8.09 (s, 1H), 7.97–7.88 (m, 2H), 7.40–7.34 (m, 2H), 5.21 (s, 1H), 4.90–4.82 (m, 1H), 4.43 (dd, J = 6.3, 2.1 Hz, 2H), 4.33–4.25 (m, 2H), 4.21 (dd, J = 10.1, 2.6 Hz, 1H), 3.95 (dd, J = 10.1, 3.4 Hz, 1H), 3.79 (s, 3H), 3.65–3.56 (m, 2H), 3.40 (s, 3H), 0.92 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[0877] O-Acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((((2-methoxyethoxy)carbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (26.6)

[0878]

[0879] Using the procedure described in Example 15.6, O-(tert-butyldimethylsilyl)-N-(2-(4-((((2-methoxyethoxy)carbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (1.202 g, 2.18 mmol) was converted to O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((((2-methoxyethoxy)carbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (1.001 g, 67%) as a colorless oil.

[0880] 11H NMR (400 MHz, CDCl3): δ 8.26 (d, J = 7.1 Hz, 1H), 8.11 (d, J = 2.6 Hz, 1H), 7.94 (dd, J = 8.3, 1.8 Hz, 2H), 7.46 (d, J = 7.8 Hz, 1H), 7.41–7.32 (m, 2H), 5.17 (s, 1H), 4.90 (dq, J = 7.0, 3.5 Hz, 1H), 4.71–4.62 (m, 1H), 4.49 (ddd, J = 11.2, 7.2, 3.9 Hz, 1H), 4.43 (d, J = 6.2 Hz, 2H), 4.33 (dd, J = 11.4, 3.6 Hz, 1H), 4.31–4.26 (m, 2H), 4.23 (dt, J = 9.9, 3.6 Hz, 1H), 3.84–3.79 (m, 1H), 3.77 (d, J = 4.0 Hz, 3H), 3.66–3.57 (m, 2H), 3.41 (s, 3H), 2.01 (s, 3H), 0.96 (s, 9H), 0.16 (s, 3H), 0.16 (s, 3H).

[0881] Methyl 2-(2-(2-(4-((((2-Methoxyethoxy)carbonyl)amino)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (26)

[0882]

[0883] Using the procedure described for compound 15, O-Acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((((2-methoxyethoxy)carbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (1.001 g, 1.47 mmole) was converted to methyl 2-(2-(2-(4-((((2-methoxyethoxy)carbonyl)amino)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.103 g, 14%).

[0884] 11H NMR (400 MHz, CDCl3): δ 10.01 (s, 1H), 8.55 (s, 1H), 8.14 (s, 1H), 8.04–7.92 (m, 2H), 7.44–7.33 (m, 2H), 6.78 (d, J = 2.2 Hz, 1H), 6.71 (s, 1H), 6.03 (d, J = 1.3 Hz, 1H), 5.50 (t, J = 1.9 Hz, 1H), 5.18 (s, 1H), 4.43 (d, J = 6.1 Hz, 2H), 4.34–4.24 (m, 2H), 3.90 (s, 3H), 3.67–3.56 (m, 2H), 3.41 (s, 3H).

[0885] Compound 27: Methyl 2-(2-(2-(3-((2-methoxyethoxymethyl)phenyl)thiazol-4-ylcarbamoyl)acry lamido)acrylate

[0886] 3-((2-Methoxyethoxy)methyl)benzonitrile (27.1)

[0887]

[0888] Dissolve 2-methoxyethanol (1.05 mL, 13.3 mmol) in DMF (20 mL) and cool to 0 °C. Add sodium hydride (60% dispersion in mineral oil, 0.532 g, 13.3 mmol) portionwise (gas evolution was observed), and stir the mixture at 0 °C for 60 minutes. Add 3-(bromomethyl)benzonitrile (2.046 g, 10.4 mmol), and warm the mixture to room temperature and stir for 18 hours. Add ethyl acetate (50 mL), and wash the mixture with water (3 x 25 mL). Dry the combined organics over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography (10 - 40% ethyl acetate / hexane gradient) to afford 3-((2-methoxyethoxy)methyl)benzonitrile (0.844, 42%) as a colorless oil.

[0889] 1 1H NMR (400 MHz, CDCl3): δ 7.67 (td, J = 1.7, 0.8 Hz, 1H), 7.62–7.54 (m, 2H), 7.45 (t, J = 7.7 Hz, 1H), 4.64–4.56 (m, 2H), 3.71–3.63 (m, 2H), 3.63–3.56 (m, 2H), 3.41 (s, 3H).

[0890] 3-((2-Methoxyethoxy)methyl)thiobenzamide (27.2)

[0891]

[0892] 3-((2-Methoxyethoxy)methyl)benzonitrile (0.844 g, 4.41 mmol) was dissolved in pyridine (5 mL). Triethylamine (0.740 mL, 5.28 mmol) and ammonium sulfide (40% aqueous solution, 1.05 mL, 6.15 mmol) were added and the mixture was heated to 50 °C for 5 h and cooled to room temperature. The mixture was concentrated and the residue was suspended in ethyl acetate (25 mL). The mixture was washed with 1 N hydrochloric acid (2 x 25 mL), then dried over magnesium sulfate, filtered and concentrated to afford 3-((2-methoxyethoxy)methyl)thiobenzamide (0.797 g, 80%) as a yellow oil.

[0893] 1 H NMR (400 MHz, DMSO-d6): δ 9.86 (s, 1H), 9.50 (s, 1H), 7.85 (q, J = 1.4, 0.9 Hz, 1H), 7.80–7.72 (m, 1H), 7.45 (dt, J = 7.6, 1.5 Hz, 1H), 7.39 (t, J = 7.6 Hz, 1H), 4.52 (s, 2H), 3.62–3.54 (m, 2H), 3.53–3.45 (m, 2H), 3.26 (s, 3H).

[0894] Ethyl 2-(3-((2-methoxyethoxy)methyl)phenyl)thiazole-4-carboxylate (27.3)

[0895]

[0896] 3-((2-Methoxyethoxy)methyl)thiobenzamide (0.797 g, 3.54 mmol) was dissolved in ethanol. Ethyl bromopyruvate (0.490 mL, 3.90 mmol) was added and the mixture was heated to 80 °C for 4 h. The mixture was cooled to room temperature and concentrated. The crude residue was purified by silica gel chromatography (20–50% ethyl acetate / hexane gradient) to afford ethyl 2-(3-((2-methoxyethoxy)methyl)phenyl)thiazole-4-carboxylate (0.421 g, 37%) as a yellow oil.

[0897] 11H NMR (400 MHz, CDCl3): δ 8.16 (s, 1H), 8.00 (td, J = 1.7, 0.7 Hz, 1H), 7.92 (dt, J = 7.4, 1.7 Hz, 1H), 7.51–7.39 (m, 2H), 4.64 (s, 2H), 4.45 (q, J = 7.1 Hz, 2H), 3.70–3.62 (m, 2H), 3.62–3.55 (m, 2H), 3.41 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H).

[0898] O-(tert-Butyldimethylsilyl)-N-(2-(3-((2-methoxyethoxy)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (27.4)

[0899]

[0900] Using the procedure described in Example 19.3, ethyl 2-(3-((2-methoxyethoxy)methyl)phenyl)thiazole-4-carboxylate (0.421 g, 1.31 mmol) was converted to O-(tert-butyldimethylsilyl)-N-(2-(3-((2-methoxyethoxy)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.475 g, 71%) as a thick colorless oil.

[0901] 1 1H NMR (400 MHz, CDCl3): δ 8.21 (d, J = 8.7 Hz, 1H), 8.11 (s, 1H), 7.95–7.87 (m, 2H), 7.52–7.40 (m, 2H), 4.87 (ddd, J = 8.7, 3.4, 2.7 Hz, 1H), 4.65 (s, 2H), 4.22 (dd, J = 10.1, 2.7 Hz, 1H), 3.95 (dd, J = 10.1, 3.4 Hz, 1H), 3.79 (s, 3H), 3.71–3.64 (m, 2H), 3.64–3.58 (m, 2H), 3.41 (s, 3H), 0.92 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[0902] O-Acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(3-((2-methoxyethoxy)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (27.5)

[0903]

[0904] Using the procedure described in Example 15.6, O-(tert-butyldimethylsilyl)-N-(2-(3-((2-methoxyethoxy)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.475 g, 0.934 mmol) was converted to O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(3-((2-methoxyethoxy)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.415 g, 70%) as a colorless oil.

[0905] 1 H NMR (400 MHz, CDCl3): δ 8.24 (d, J = 7.1 Hz, 1H), 8.12 (d, J = 2.5 Hz, 1H), 7.92 (ddt, J = 5.2, 3.4, 1.7 Hz, 2H), 7.51–7.40 (m, 3H), 4.95–4.85 (m, 1H), 4.72–4.66 (m, 1H), 4.65 (s, 2H), 4.49 (ddd, J = 11.3, 6.1, 3.9 Hz, 1H), 4.34 (dd, J = 11.4, 3.6 Hz, 1H), 4.22 (ddd, J = 9.8, 3.8, 2.8 Hz, 1H), 3.84–3.79 (m, 1H), 3.77 (s, 3H), 3.70–3.64 (m, 2H), 3.64–3.56 (m, 2H), 3.41 (s, 3H), 2.02 (s, 3H), 0.96 (s, 9H), 0.17 (s, 3H), 0.16 (s, 3H).

[0906] Methyl 2-(2-(2-(3-((2-methoxyethoxy)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (27)

[0907]

[0908] Using the procedure described for Compound 15, O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(3-((2-methoxyethoxy)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.415 g, 0.651 mmol) was converted to methyl 2-(2-(2-(3-((2-methoxyethoxy)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (0.153 g, 53%) as a white solid.

[0909] 11H NMR (400 MHz, CDCl3): δ 10.00 (s, 1H), 8.55 (s, 1H), 8.16 (s, 1H), 7.97 (dt, J = 6.5, 2.3 Hz, 1H), 7.94 (d, J = 1.7 Hz, 1H), 7.51–7.42 (m, 2H), 6.78 (d, J = 2.2 Hz, 1H), 6.72 (s, 1H), 6.03 (d, J = 1.3 Hz, 1H), 5.51 (t, J = 1.9 Hz, 1H), 4.67 (s, 2H), 3.90 (s, 3H), 3.74–3.66 (m, 2H), 3.66–3.57 (m, 2H), 3.42 (s, 3H).

[0910] Compound 28: Methyl 2-(2-(2-(3-(isobutylcarbamoyl)piperidin-1-yl)thiazol-4-ylcarbamoyl)acry lamido)acrylate

[0911] tert-Butyl 3-(isobutylcarbamoyl)piperidine-1-carboxylate (28.1)

[0912]

[0913] Dissolve 1-(tert-butoxycarbonyl)piperidine-3-carboxylic acid (0.754 g, 3.29 mmol) in DCM (6.5 mL). Add isobutylamine (0.390 mL, 3.92 mmol) then add N,N-diisopropylethylamine (1.15 mL, 6.60 mmol), HOBt·H2O (0.603 g, 3.94 mmol) and EDC·HCl (0.750 g, 3.91 mmol). Stir the mixture at room temperature for 3 days. Add water (25 mL) and extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography (20 - 50% ethyl acetate / hexane gradient) to afford tert-butyl 3-(isobutylcarbamoyl)piperidine-1-carboxylate (0.817 g, 87%) as a white solid.

[0914] 1 1H NMR (400 MHz, CDCl3): δ 4.07–3.61 (m, 2H), 3.26 (s, 1H), 3.08 (t, J = 6.4 Hz, 2H), 2.29 (s, 1H), 1.85 (d, J = 29.1 Hz, 2H), 1.76 (p, J = 6.7 Hz, 1H), 1.62 (s, 1H), 1.46 (s, 9H), 0.91 (dd, J = 6.7, 1.1 Hz, 6H).

[0915] Ethyl 2-(3-(isobutylcarbamoyl)piperidin-1-yl)thiazole-4-carboxylate (28.2)

[0916]

[0917] Dissolve tert-butyl 3-(isobutylcarbamoyl)piperidine-1-carboxylate (0.817 g, 2.87 mmol) in DCM (5.5 mL). Add HCl (4 M solution in 1,4-dioxane, 2.80 mL, 11.2 mmol), and stir the mixture at room temperature for 3 h, then concentrate. Dissolve the residue in DMA (3 mL), and add ethyl 2-bromothiazole-4-carboxylate (0.749 g, 3.17 mmol) and triethylamine (0.490 mL, 3.50 mmol). Heat the mixture at 80 °C for 18 h, and cool to room temperature. Add ethyl acetate (25 mL), and wash the mixture with water (3 x 25 mL). Dry the organic layer over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography (30 - 70% ethyl acetate / hexane gradient) to afford ethyl 2-(3-(isobutylcarbamoyl)piperidin-1-yl)thiazole-4-carboxylate (0.445 g, 46%) as a white solid.

[0918] 1 H NMR (400 MHz, CDCl3): δ 7.43 (s, 1H), 5.93 (s, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.05 (ddd, J = 13.3, 3.2, 2.0 Hz, 1H), 3.83–3.74 (m, 1H), 3.47 (dd, J = 13.2, 9.5 Hz, 1H), 3.24–3.14 (m, 1H), 3.14–3.01 (m, 2H), 2.45 (tt, J = 9.3, 4.5 Hz, 1H), 1.93 (ddd, J = 9.5, 8.0, 4.3 Hz, 2H), 1.85–1.71 (m, 2H), 1.68–1.59 (m, 1H), 1.37 (t, J = 7.1 Hz, 3H), 0.89 (d, J = 6.7 Hz, 6H).

[0919] O-(tert-Butyldimethylsilyl)-N-(2-(3-(isobutylcarbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (28.3)

[0920]

[0921] Using the procedure described in Example 19.3, ethyl 2-(3-(isobutylcarbamoyl)piperidin-1-yl)thiazole-4-carboxylate (0.445 g, 1.34 mmol) was converted into a mixture of diastereomers of O-(tert-butyldimethylsilyl)-N-(2-(3-(isobutylcarbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.470 g, 67%) as a thick colorless oil.

[0922] 1 H NMR (400 MHz, CDCl3): δ 7.93 (dd, J = 17.6, 8.7 Hz, 1H), 7.38 (d, J = 2.1 Hz, 1H), 5.84 (dd, J = 13.7, 6.7 Hz, 1H), 4.79 (ddt, J = 9.5, 6.4, 3.0 Hz, 1H), 4.19–4.13 (m, 1H), 3.99 (dd, J = 13.2, 4.0 Hz, 1H), 3.93–3.79 (m, 2H), 3.76 (d, J = 0.8 Hz, 3H), 3.47 (ddd, J = 48.4, 13.3, 9.5 Hz, 1H), 3.25–3.00 (m, 3H), 2.46 (qt, J = 8.7, 4.1 Hz, 1H), 1.93 (dq, J = 11.6, 3.6, 2.3 Hz, 2H), 1.77 (dtd, J = 13.4, 6.8, 5.1 Hz, 2H), 1.67 (dt, J = 9.2, 4.6 Hz, 2H), 0.90 (dd, J = 6.7, 4.7 Hz, 6H), 0.87 (d, J = 1.6 Hz, 9H), 0.04 (d, 3H), 0.02 (d, 3H).

[0923] O-Acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(3-(isobutylcarbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (28.4)

[0924]

[0925] Using the procedure described in Example 15.6, O-(tert-butyldimethylsilyl)-N-(2-(3-(isobutylcarbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.470 g, 0.892 mmol) was converted into O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(3-(isobutylcarbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.422 g, 72%) as a colorless oil.

[0926] 1 1H NMR (400 MHz, CDCl3): δ 7.98 (dd, J = 16.3, 6.9 Hz, 1H), 7.46 (dd, J = 14.0, 7.9 Hz, 1H), 7.40 (d, J = 1.3 Hz, 1H), 6.03–5.72 (m, 1H), 4.86 (ddt, J = 7.6, 5.4, 3.8 Hz, 1H), 4.62–4.53 (m, 1H), 4.47 (ddd, J = 11.3, 8.4, 3.9 Hz, 1H), 4.37–4.25 (m, 1H), 4.22–4.15 (m, 1H), 3.88 (dd, J = 13.1, 4.5 Hz, 1H), 3.81–3.68 (m, 4H), 3.50–3.32 (m, 1H), 3.25–2.99 (m, 3H), 2.47 (ddt, J = 15.5, 5.8, 3.4 Hz, 1H), 2.04–1.99 (m, 3H), 1.98–1.87 (m, 2H), 1.79 (ttt, J = 13.5, 6.7, 3.1 Hz, 2H), 0.92 (d, J = 1.6 Hz, 8H), 0.90 (dd, J = 6.6, 0.8 Hz, 6H), 0.14 (dt, J = 6.1, 3.3 Hz, 6H).

[0927] Methyl 2-(2-(2-(3-(isobutylcarbamoyl)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (28)

[0928]

[0929] Using the procedure described for compound 15, O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(3-(isobutylcarbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.422 g, 0.643 mmole) was converted to methyl 2-(2-(2-(3-(isobutylcarbamoyl)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.139 g, 47%).

[0930] 11H NMR (400 MHz, CDCl3): δ 9.78 (s, 1H), 8.52 (s, 1H), 7.44 (s, 1H), 6.71 (d, J = 2.1 Hz, 1H), 6.63 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.92 (t, J = 6.0 Hz, 1H), 5.43 (t, J = 1.9 Hz, 1H), 4.07 (dd, J = 13.3, 4.0 Hz, 1H), 3.90 (s, 3H), 3.77 (ddd, J = 13.7, 5.1, 3.8 Hz, 1H), 3.47–3.37 (m, 1H), 3.23 (ddd, J = 13.2, 11.0, 3.4 Hz, 1H), 3.19–3.04 (m, 2H), 2.60–2.47 (m, 1H), 1.96 (td, J = 8.3, 7.7, 3.9 Hz, 2H), 1.87–1.73 (m, 2H), 1.73–1.62 (m, 1H), 0.90 (d, J = 6.7 Hz, 6H).

[0931] Compound 29: Methyl 2-(2-(2-(4-((3-isopropoxypropyl)carbamoyl)piperidin-1-yl)thiazol-4-ylcarbam oyl)acrylamido)acrylate

[0932] Ethyl 2-(4-(tert-butoxycarbonyl)piperidin-1-yl)thiazole-4-carboxylate (29.1)

[0933]

[0934] Dissolve tert-butyl piperidine-4-carboxylate hydrochloride (2.000 g, 9.02 mmole) in DMA (10 mL). Add ethyl 2-bromothiazole-4-carboxylate (2.251 g, 9.53 mmole) and triethylamine (1.40 mL, 9.99 mmole), and heat the mixture at 80 °C for 18 h, then cool to room temperature. Add ethyl acetate (50 mL), and wash the mixture with water (3 x 25 mL). Dry the organic layer over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography (10–30% ethyl acetate / hexane gradient) to afford ethyl 2-(4-(tert-butoxycarbonyl)piperidin-1-yl)thiazole-4-carboxylate (1.735 g, 57%) as a pale yellow solid.

[0935] 11H NMR (400 MHz, CDCl3): δ 7.43 (s, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.02–3.91 (m, 2H), 3.14 (ddd, J = 13.0, 11.1, 3.2 Hz, 2H), 2.43 (tt, J = 10.7, 3.8 Hz, 1H), 1.98 (dtt, J = 13.5, 3.9, 2.0 Hz, 2H), 1.85–1.73 (m, 2H), 1.45 (s, 9H), 1.37 (t, J = 7.1 Hz, 3H).

[0936] Ethyl 2-(4-((3-isopropoxypropyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxylate (29.2)

[0937]

[0938] Ethyl 2-(4-(tert-butoxycarbonyl)piperidin-1-yl)thiazole-4-carboxylate (0.557 g, 1.64 mmol) was dissolved in DCM (3.2 mL). HCl (4 M solution in 1,4-dioxane, 1.60 mL, 6.40 mmol) was added and the solution was stirred at room temperature for 18 h and then concentrated. The residue was suspended in DCM (3.2 mL). N,N-Diisopropylethylamine (0.560 mL, 3.22 mmol) was added and then 3-isopropoxypropan-1-amine (0.270 mL, 1.95 mmol), HOBt·H2O (0.295 g, 1.93 mmol) and EDC·HCl (0.382 g, 1.99 mmol) were added. The mixture was stirred at room temperature for 18 h and water (25 mL) was added. The mixture was extracted with DCM (3 x 10 mL). The combined organics were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography (70-100% ethyl acetate / hexane gradient) to afford ethyl 2-(4-((3-isopropoxypropyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxylate (0.497 g, 79%) as a white solid.

[0939] 11H NMR (400 MHz, CDCl3): δ 7.44 (s, 1H), 6.46 (s, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.08 (dt, J = 13.4, 4.2 Hz, 2H), 3.62–3.50 (m, 3H), 3.44–3.34 (m, 2H), 3.07 (ddd, J = 13.0, 11.8, 3.1 Hz, 2H), 2.27 (tt, J = 11.5, 3.6 Hz, 1H), 2.02–1.92 (m, 2H), 1.86–1.71 (m, 4H), 1.37 (t, J = 7.1 Hz, 3H), 1.16 (d, J = 6.1 Hz, 6H).

[0940] O-(tert-Butyldimethylsilyl)-N-(2-(4-((3-isopropoxypropyl)carbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (29.3)

[0941]

[0942] Using the procedure described in Example 19.3, ethyl 2-(4-((3-isopropoxypropyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxylate (0.497 g, 1.30 mmole) was converted to O-(tert-butyldimethylsilyl)-N-(2-(4-((3-isopropoxypropyl)carbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.418 g, 56%) as a thick colorless oil.

[0943] 1 1H NMR (400 MHz, CDCl3): δ 7.96 (d, J = 8.8 Hz, 1H), 7.38 (s, 1H), 6.48 (t, J = 5.2 Hz, 1H), 4.78 (ddd, J = 8.8, 3.4, 2.6 Hz, 1H), 4.19–4.14 (m, 1H), 4.08–3.96 (m, 2H), 3.88 (dd, J = 10.0, 3.4 Hz, 1H), 3.76 (s, 3H), 3.62–3.51 (m, 3H), 3.44–3.35 (m, 2H), 3.12–2.98 (m, 2H), 2.28 (tt, J = 11.5, 3.6 Hz, 1H), 2.01–1.91 (m, 2H), 1.87–1.70 (m, 5H), 1.17 (d, J = 6.1 Hz, 6H), 0.88 (s, 9H), 0.05 (s, 3H), 0.03 (s, 3H).

[0944] O - Acetyl - N - (O - (tert - butyldimethylsilyl) - N - (2 - (4 - ((3 - isopropoxypropyl)carbamoyl)piperidin - 1 - yl)thiazole - 4 - carbonyl) - L - seryl) - L - serine methyl ester (29.4)

[0945]

[0946] Using the procedure described in Example 15.6, O - (tert - butyldimethylsilyl) - N - (2 - (4 - ((3 - isopropoxypropyl)carbamoyl)piperidin - 1 - yl)thiazole - 4 - carbonyl) - L - serine methyl ester (0.418 g, 0.732 mmol) was converted to O - acetyl - N - (O - (tert - butyldimethylsilyl) - N - (2 - (4 - ((3 - isopropoxypropyl)carbamoyl)piperidin - 1 - yl)thiazole - 4 - carbonyl) - L - seryl) - L - serine methyl ester (0.276 g, 54%) as a colorless oil.

[0947] 1 H NMR (400 MHz, CDCl3): δ 7.99 (d, J = 7.1 Hz, 1H), 7.43 (d, J = 7.8 Hz, 1H), 7.39 (d, J = 3.0 Hz, 1H), 6.47 (t, J = 5.1 Hz, 1H), 4.87 (dq, J = 8.2, 4.0 Hz, 1H), 4.63–4.54 (m, 1H), 4.51–4.43 (m, 1H), 4.31 (dd, J = 11.4, 3.7 Hz, 1H), 4.23–4.16 (m, 1H), 4.03 (tt, J = 15.8, 2.7 Hz, 2H), 3.76 (d, J = 2.6 Hz, 3H), 3.75–3.69 (m, 1H), 3.62–3.52 (m, 3H), 3.40 (dt, J = 6.0, 5.0 Hz, 2H), 3.05 (td, J = 12.6, 3.0 Hz, 2H), 2.28 (tt, J = 11.5, 3.6 Hz, 1H), 2.02 (d, J = 2.8 Hz, 3H), 2.00–1.90 (m, 2H), 1.85–1.72 (m, 4H), 1.17 (d, J = 6.1 Hz, 6H), 0.92 (s, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[0948] Methyl 2 - (2 - (2 - (4 - ((3 - isopropoxypropyl)carbamoyl)piperidin - 1 - yl)thiazole - 4 - carboxamido)acrylamido)acrylate (29)

[0949]

[0950] Using the procedure described for compound 15, O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((3-isopropoxypropyl)carbamoyl)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.276 g, 0.394 mmole) was converted to methyl 2-(2-(2-(4-((3-isopropoxypropyl)carbamoyl)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.088 g, 44%).

[0951] 1 H NMR (400 MHz, CDCl3): δ 9.72 (s, 1H), 8.51 (s, 1H), 7.43 (s, 1H), 6.72 (d, J = 2.1 Hz, 1H), 6.66 (s, 1H), 6.46 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.43 (t, J = 1.8 Hz, 1H), 4.10–4.01 (m, 2H), 3.89 (s, 3H), 3.63–3.50 (m, 3H), 3.46–3.34 (m, 2H), 3.08 (ddd, J = 13.0, 11.8, 3.0 Hz, 2H), 2.29 (tt, J = 11.5, 3.7 Hz, 1H), 2.02–1.92 (m, 2H), 1.89–1.72 (m, 4H), 1.17 (d, J = 6.1 Hz, 6H).

[0952] Compound 30: Methyl 2-(2-(2-(4-(((benzylcarbamoyl)oxy)methyl)phenyl)thiazol-4-ylcarbamoyl) acrylamido)acrylate

[0953] 4-Cyanobenzyl 1H-imidazole-1-carboxylate (30.1)

[0954]

[0955] Following the literature procedure (RSC Adv., 2014, 4, 13012-13017), 4-(hydroxymethyl)benzonitrile (2.000 g, 15.0 mmole) was dissolved in THF (30 mL). N,N'-Carbonyldiimidazole (2.924 g, 18.0 mmole) was added and the solution was stirred at room temperature for 2 days. Water (50 mL) was added and the mixture was extracted with ethyl acetate (3 x 15 mL). The combined organics were washed successively with water (1 x 25 mL) and saturated aqueous sodium chloride (1 x 25 mL), then dried over magnesium sulfate, filtered and concentrated to afford 4-cyanobenzyl 1H-imidazole-1-carboxylate as a brown solid (3.489 g, 100%).

[0956] 11H NMR (400 MHz, CDCl3): δ 8.16 (t, J = 1.1 Hz, 1H), 7.77–7.70 (m, 2H), 7.60–7.52 (m, 2H), 7.44 (t, J = 1.5 Hz, 1H), 7.13–7.05 (m, 1H), 5.48 (s, 2H).

[0957] 4-Cyanobenzyl benzylcarbamate (30.2)

[0958]

[0959] 4-Cyanobenzyl 1H-imidazole-1-carboxylate (0.756 g, 3.33 mmol) was dissolved in DMF (6 mL). Benzylamine (0.400 mL, 3.66 mmol) and N,N-diisopropylethylamine (0.630 mL, 3.62 mmol) were added, and the solution was heated to 70 °C for 20 h. The mixture was cooled to room temperature and diluted with ethyl acetate (25 mL). The mixture was washed with water (3 x 25 mL), dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography (10-40% ethyl acetate / hexane gradient) to afford 4-cyanobenzyl benzylcarbamate (0.764 g, 86%) as a colorless oil.

[0960] 1 1H NMR (400 MHz, CDCl3): δ 7.63 (d, J = 7.9 Hz, 2H), 7.45 (d, J = 7.9 Hz, 2H), 7.38–7.22 (m, 5H), 5.17 (s, 3H), 4.39 (d, J = 6.0 Hz, 2H).

[0961] 4-Thiocarbamoylbenzyl benzylcarbamate (30.3)

[0962]

[0963] 4-Cyanobenzyl benzylcarbamate (0.764 g, 2.87 mmol) was dissolved in pyridine (3 mL). Triethylamine (0.450 mL, 3.21 mmol) and ammonium sulfide (40% aqueous solution, 0.590 mL, 3.45 mmol) were added, and the mixture was heated to 50 °C for 4 h, then cooled to room temperature and concentrated. The residue was suspended in ethyl acetate (25 mL) and washed with 1N hydrochloric acid (2 x 25 mL). The slurry was filtered to afford a yellow solid. The filtrate was dried over magnesium sulfate, filtered, and concentrated to afford a yellow solid. The two solids were combined to afford 4-thiocarbamoylbenzyl benzylcarbamate (0.707 g, 82%) as a yellow solid.

[0964] 1 1H NMR (400 MHz, DMSO-d6): δ 9.87 (s, 1H), 9.49 (s, 1H), 7.93–7.81 (m, 3H), 7.37 (d, J = 8.1 Hz, 2H), 7.35–7.28 (m, 2H), 7.25 (dt, J = 8.3, 2.3 Hz, 3H), 5.08 (s, 2H), 4.21 (d, J = 6.2 Hz, 2H).

[0965] Ethyl 2-(4-(((benzylcarbamoyl)oxy)methyl)phenyl)thiazole-4-carboxylate (30.4)

[0966]

[0967] Dissolve 4-thiocarbamoylbenzyl N-benzylcarbamate (0.707 g, 2.35 mmole) in ethanol (12 mL). Add ethyl bromopyruvate (0.360 mL, 2.87 mmole) and heat the mixture at 80 °C for 3 h, then cool to room temperature and concentrate. Suspend the residue in ethyl acetate (25 mL) and wash successively with saturated aqueous sodium bicarbonate (2 x 25 mL) and water (1 x 25 mL). Extract the combined aqueous washes with ethyl acetate (1 x 15 mL). Dry the combined organics over magnesium sulfate, filter and concentrate to afford ethyl 2-(4-(((benzylcarbamoyl)oxy)methyl)phenyl)thiazole-4-carboxylate (0.935 g, 100%) as a yellow solid.

[0968] 1 1H NMR (400 MHz, CDCl3): δ 8.15 (s, 1H), 7.99 (d, J = 7.9 Hz, 2H), 7.44 (t, J = 5.6 Hz, 2H), 7.38–7.27 (m, 5H), 5.18 (s, 3H), 4.45 (q, J = 7.1 Hz, 2H), 4.41–4.34 (m, 2H), 1.43 (t, J = 7.2 Hz, 3H).

[0969] N-(2-(4-(((benzylcarbamoyl)oxy)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (30.5)

[0970]

[0971] Using the procedure described in Example 19.3, ethyl 2-(4-(((benzylcarbamoyl)oxy)methyl)phenyl)thiazole-4-carboxylate (0.935 g, 2.36 mmole) was converted to N-(2-(4-(((benzylcarbamoyl)oxy)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (0.740 g, 54%) as a yellow oil.

[0972] 1 H NMR (400 MHz, CDCl3): δ 8.22 (d, J = 8.7 Hz, 1H), 8.10 (s, 1H), 7.95 (d, J = 7.9 Hz, 2H), 7.44 (d, J = 7.9 Hz, 2H), 7.38–7.27 (m, 5H), 5.21 (s, 1H), 5.19 (s, 2H), 4.86 (dt, J = 8.7, 3.0 Hz, 1H), 4.41 (d, J = 6.0 Hz, 2H), 4.21 (dd, J = 10.0, 2.6 Hz, 1H), 3.95 (dd, J = 10.0, 3.3 Hz, 1H), 3.79 (s, 3H), 0.92 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[0973] O-Acetyl-N-(N-(2-(4-(((benzylcarbamoyl)oxy)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (30.6)

[0974]

[0975] Using the procedure described in Example 15.6, N-(2-(4-(((benzylcarbamoyl)oxy)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (0.740 g, 1.27 mmole) was converted to O-acetyl-N-(N-(2-(4-(((benzylcarbamoyl)oxy)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (0.535 g, 59%) as a pale yellow gel. 11H NMR (400 MHz, CDCl3): δ 8.26 (d, J = 7.1 Hz, 1H), 8.12 (d, J = 2.5 Hz, 1H), 8.00–7.91 (m, 2H), 7.45 (t, J = 8.6 Hz, 3H), 7.40–7.27 (m, 5H), 5.19 (s, 2H), 5.13 (s, 1H), 4.90 (tt, J = 7.4, 3.8 Hz, 1H), 4.67 (td, J = 7.4, 3.8 Hz, 1H), 4.49 (ddd, J = 11.0, 7.0, 4.0 Hz, 1H), 4.45–4.37 (m, 2H), 4.34 (dd, J = 11.4, 3.6 Hz, 1H), 4.23 (dt, J = 9.9, 3.5 Hz, 1H), 3.85–3.78 (m, 1H), 3.77 (d, J = 4.2 Hz, 3H), 2.02 (s, 3H), 0.96 (s, 9H), 0.17 (s, 3H), 0.16 (s, 3H).

[0976] Methyl 2-(2-(2-(4-(((benzylcarbamoyl)oxy)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (30)

[0977]

[0978] Using the procedure described for compound 15, O-acetyl-N-(N-(2-(4-(((benzylcarbamoyl)oxy)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-seryl)-L-serine methyl ester (0.535 g, 0.750 mmol) was converted to methyl 2-(2-(2-(4-(((benzylcarbamoyl)oxy)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.079 g, 20%).

[0979] 1 1H NMR (400 MHz, CDCl3): δ 10.02 (s, 1H), 8.55 (s, 1H), 8.15 (s, 1H), 8.00 (d, J = 8.0 Hz, 2H), 7.46 (d, J = 7.9 Hz, 2H), 7.40–7.28 (m, 5H), 6.78 (d, J = 2.2 Hz, 1H), 6.71 (s, 1H), 6.03 (d, J = 1.3 Hz, 1H), 5.50 (t, J = 1.9 Hz, 1H), 5.19 (s, 2H), 5.11 (s, 1H), 4.41 (d, J = 6.0 Hz, 2H), 3.90 (s, 3H).

[0980] Compound 31: (R)-Methyl 2-(2-(2-(3-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazol-4-ylcarbamoyl)acrylamido)acrylate

[0981] (R)-Ethyl 2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (31.1)

[0982]

[0983] (R)-tert-Butyl piperidin-3-ylcarbamate was dissolved in DMA. Ethyl 2-bromothiazole-4-carboxylate and triethylamine were added, and the mixture was heated at 80 °C for 20 h, then cooled to room temperature and diluted with ethyl acetate (25 mL). The mixture was washed with water (3 x 25 mL), and the organic matter was dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford (R)-ethyl 2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (1.399 g, 79%) as a white solid.

[0984] 1 H NMR (400 MHz, CDCl3) δ 7.44 (s, 1H), 4.73 (s, 1H), 4.35 (q, J = 7.1 Hz, 2H), 3.80 (s, 1H), 3.71 (d, J = 11.9 Hz, 1H), 3.62 (s, 1H), 3.45 (s, 1H), 3.30 (d, J = 9.1 Hz, 1H), 1.97–1.87 (m, 1H), 1.81 (ddt, J = 10.8, 7.2, 3.5 Hz, 1H), 1.76–1.63 (m, 1H), 1.60 (s, 1H), 1.50 (d, J = 7.7 Hz, 9H), 1.37 (t, J = 7.1 Hz, 3H).

[0985] (R)-Ethyl 2-(3-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (31.2)

[0986]

[0987] Ethyl (R)-2-(3-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate was dissolved in DCM. HCl (4 M solution in 1,4-dioxane) was added and the mixture was stirred at room temperature for 2 h and concentrated. The residue was dissolved in DMF. 2-Methoxyethyl 1H-imidazole-1-carboxylate and N,N-diisopropylethylamine were added and the mixture was heated to 70 °C for 3 h, then cooled to room temperature and diluted with ethyl acetate (40 mL). The mixture was washed with water (3 x 25 mL) and the organic layer was dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford ethyl (R)-2-(3-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (0.613 g, 44%) as a white solid.

[0988] 1 H NMR (400 MHz, CDCl3) δ 7.45 (s, 1H), 4.99 (d, J = 7.7 Hz, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.23 (t, J = 4.6 Hz, 2H), 3.93–3.78 (m, 1H), 3.77–3.67 (m, 1H), 3.67–3.61 (m, 1H), 3.61 - 3.53 (m, 2H), 3.46 - 3.42 (m, 1H), 3.39 (s, 3H), 3.32 (dd, J = 12.7, 7.1 Hz, 1H), 1.90 (qd, J = 7.3, 3.5 Hz, 1H), 1.83 (ddt, J = 14.4, 7.3, 3.6 Hz, 1H), 1.76–1.66 (m, 1H), 1.66–1.55 (m, 1H), 1.37 (t, J = 7.1 Hz, 3H).

[0989] O-(tert-Butyldimethylsilyl)-N-(2-((R)-3-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (31.3)

[0990]

[0991] Using the procedure described in Example 19.3, ethyl (R)-2-(3-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (0.613 g, 1.72 mmol) was converted to O-(tert-butyldimethylsilyl)-N-(2-((R)-3-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.397 g, 42%) as a yellow oil.

[0992] 1 1H NMR (400 MHz, CDCl3) δ 7.93 (d, J = 8.7 Hz, 1H), 7.39 (s, 1H), 4.99 (d, J = 8.0 Hz, 1H), 4.83–4.73 (m, 1H), 4.23 (q, J = 3.8 Hz, 2H), 4.16 (dd, J = 10.0, 2.7 Hz, 1H), 3.93–3.83 (m, 2H), 3.76 (s, 3H), 3.68 (dd, J = 12.6, 3.7 Hz, 1H), 3.59 (t, J = 4.7 Hz, 2H), 3.54 (d, J = 6.3 Hz, 1H), 3.44 - 3.37 (m, 1H), 3.39 (s, 3H), 3.29 (dd, J = 12.7, 7.0 Hz, 1H), 1.92 (td, J = 8.3, 3.8 Hz, 1H), 1.82 (dp, J = 10.9, 3.6 Hz, 1H), 1.77–1.68 (m, 1H), 1.68–1.57 (m, 1H), 0.88 (s, 9H), 0.05 (s, 3H), 0.03 (s, 3H).

[0993] O - Acetyl - N - (O - (tert - butyldimethylsilyl) - N - (2 - ((R) - 3 - ((((2 - methoxyethoxy)carbonyl)amino)piperidin - 1 - yl)thiazole - 4 - carbonyl) - L - seryl) - L - serine methyl ester (31.4)

[0994]

[0995] Using the procedure described in Example 15.6, O - (tert - butyldimethylsilyl) - N - (2 - ((R) - 3 - ((((2 - methoxyethoxy)carbonyl)amino)piperidin - 1 - yl)thiazole - 4 - carbonyl) - L - serine methyl ester (0.397 g, 0.729 mmole) was converted to O - acetyl - N - (O - (tert - butyldimethylsilyl) - N - (2 - ((R) - 3 - ((((2 - methoxyethoxy)carbonyl)amino)piperidin - 1 - yl)thiazole - 4 - carbonyl) - L - seryl) - L - serine methyl ester (0.367 g, 73%) as a pale yellow gel.

[0996] 11H NMR (400 MHz, CDCl3) δ 7.95 (d, J = 7.2 Hz, 1H), 7.44 (d, J = 7.8 Hz, 1H), 7.40 (s, 1H), 4.98 (t, J = 10.1 Hz, 1H), 4.88 (dt, J = 7.8, 3.8 Hz, 1H), 4.59 (td, J = 7.3, 3.7 Hz, 1H), 4.47 (ddd, J = 12.0, 8.1, 4.0 Hz, 1H), 4.31 (dd, J = 11.4, 3.7 Hz, 1H), 4.23 (d, J = 4.4 Hz, 2H), 4.18 (ddd, J = 9.8, 3.7, 1.6 Hz, 1H), 3.91–3.81 (m, 1H), 3.76 (s, 3H), 3.75–3.70 (m, 1H), 3.62–3.52 (m, 3H), 3.44 - 3.39 (m, 1H), 3.39 (s, 3H), 3.31–3.14 (m, 1H), 2.05 (s, 3H), 1.98–1.87 (m, 1H), 1.83 (ddt, J = 14.1, 7.0, 3.3 Hz, 1H), 1.72 (dq, J = 9.6, 5.0, 4.5 Hz, 1H), 0.92 (s, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[0997] (R)-Methyl 2-(2-(2-(3-(((2-Methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (31)

[0998]

[0999] Using the procedure described for compound 15, O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-((R)-3-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.361 g, 0.536 mmol) was converted to (R)-methyl 2-(2-(2-(3-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (0.116 g, 45%) as a colorless gel.

[1000] 11H NMR (400 MHz, CDCl3) δ 9.69 (s, 1H), 8.51 (s, 1H), 7.44 (s, 1H), 6.71 (d, J = 2.1 Hz, 1H), 6.67 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.44 (t, J = 1.8 Hz, 1H), 5.00 (d, J = 7.9 Hz, 1H), 4.24 (dd, J = 6.9, 2.6 Hz, 2H), 3.92 - 3.83 (m, 1H), 3.89 (s, 3H), 3.67 (d, J = 15.8 Hz, 1H), 3.58 (t, J = 4.6 Hz, 2H), 3.44 (s, 1H), 3.39 (s, 3H), 3.35 (t, J = 6.3 Hz, 1H), 1.89 (d, J = 3.0 Hz, 1H), 1.84 (dt, J = 7.1, 3.1 Hz, 1H), 1.78–1.62 (m, 3H).

[1001] Compound 32: Methyl 2-(2-(2-(4-((((3-methoxypropyl)carbamoyl)oxy)methyl)piperidin-1-yl) thiazole-4-carboxamido)acrylamido)acrylate

[1002] tert-Butyl 4-(((1H-imidazole-1-carbonyl)oxy)methyl)piperidine-1-carboxylate (32.1)

[1003]

[1004] Using the procedure described in Example 27.1, tert-butyl 4-(hydroxymethyl)piperidine-1-carboxylate (2.007 g, 9.32 mmole) was converted to tert-butyl 4-(((1H-imidazole-1-carbonyl)oxy)methyl)piperidine-1-carboxylate (3.389 g) as a pale yellow oil.

[1005] 1 1H NMR (400 MHz, CDCl3) δ 8.14 (t, J = 1.1 Hz, 1H), 7.42 (t, J = 1.5 Hz, 1H), 7.08 (dd, J = 1.6, 0.9 Hz, 1H), 4.29 (d, J = 6.6 Hz, 2H), 4.24–4.13 (m, 2H), 2.74 (t, J = 12.8 Hz, 2H), 2.03–1.93 (m, 1H), 1.81–1.70 (m, 2H), 1.46 (s, 9H), 1.34–1.26 (m, 2H).

[1006] tert-Butyl 4-((((3-methoxypropyl)carbamoyl)oxy)methyl)piperidine-1-carboxylate (32.2)

[1007]

[1008] Dissolve tert-butyl 4-(((1H-imidazol-1-ylcarbonyl)oxy)methyl)piperidine-1-carboxylate (0.994 g, 3.21 mmol) in DMF (6 mL). Add 3-methoxypropylamine (0.365 mL, 3.58 mmol) and N,N-diisopropylethylamine (0.680 mL, 3.90 mmol), and heat the mixture to 70 °C for 18 h, then cool to room temperature and dilute with ethyl acetate (25 mL). Wash the mixture with water (3 x 25 mL), and dry, filter, and concentrate the organic layer over magnesium sulfate. Purify the crude residue by silica gel chromatography to afford tert-butyl 4-((((3-methoxypropyl)carbamoyl)oxy)methyl)piperidine-1-carboxylate (0.779 g, 73%) as a colorless oil.

[1009] 1 H NMR (400 MHz, CDCl3) δ 5.10 (s, 1H), 4.17 - 4.05 (m, 2H), 3.91 (d, J = 6.5 Hz, 2H), 3.46 (t, J = 5.8 Hz, 2H), 3.34 (s, 3H), 3.28 (q, J = 6.3 Hz, 2H), 2.77–2.61 (m, 2H), 1.83–1.73 (m, 3H), 1.70 (s, 2H), 1.45 (s, 9H), 1.22–1.10 (m, 2H).

[1010] Ethyl 2-(4-((((3-methoxypropyl)carbamoyl)oxy)methyl)piperidin-1-yl)thiazole-4-carboxylate (32.3)

[1011]

[1012] Dissolve tert-butyl 4-((((3-methoxypropyl)carbamoyl)oxy)methyl)piperidine-1-carboxylate (0.779 g, 2.36 mmol) in DCM (5 mL). Add HCl (4 M solution in 1,4-dioxane, 2.40 mL, 9.60 mmol), and stir the mixture at room temperature for 2 h, then concentrate. Dissolve the residue in DMA (3 mL). Add ethyl 2-bromothiazole-4-carboxylate (0.564 g, 2.39 mmol) and triethylamine (0.660 mL, 4.71 mmol), and heat the mixture to 80 °C for 20 h, then cool to room temperature and dilute with ethyl acetate (25 mL). Wash the mixture with water (3 x 25 mL), and dry, filter and concentrate the organic matter over magnesium sulfate. Purify the crude residue by silica gel chromatography to afford ethyl 2-(4-((((3-methoxypropyl)carbamoyl)oxy)methyl)piperidin-1-yl)thiazole-4-carboxylate (0.460 g, 51%) as a light brown solid.

[1013] 1 H NMR (400 MHz, CDCl3) δ 7.42 (s, 1H), 5.08 (s, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.07 (dt, J = 12.7, 3.4 Hz, 2H), 3.95 (d, J = 6.2 Hz, 2H), 3.46 (t, J = 5.8 Hz, 2H), 3.34 (s, 3H), 3.29 (q, J = 6.2 Hz, 2H), 3.03 (td, J = 12.6, 2.8 Hz, 2H), 1.95–1.67 (m, 5H), 1.37 (t, J = 7.1 Hz, 5H).

[1014] O-(tert-Butyldimethylsilyl)-N-(2-(4-((((3-methoxypropyl)carbamoyl)oxy)methyl)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (32.4)

[1015]

[1016] Using the procedure described in Example 19.3, convert ethyl 2-(4-((((3-methoxypropyl)carbamoyl)oxy)methyl)piperidin-1-yl)thiazole-4-carboxylate (0.460 g, 1.19 mmol) into O-(tert-butyldimethylsilyl)-N-(2-(4-((((3-methoxypropyl)carbamoyl)oxy)methyl)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.447 g, 66%) as a pale yellow oil.

[1017] 11H NMR (400 MHz, CDCl3) δ 7.97 (d, J = 8.8 Hz, 1H), 7.36 (s, 1H), 5.08 (s, 1H), 4.82–4.74 (m, 1H), 4.16 (dd, J = 10.0, 2.6 Hz, 1H), 4.02 (d, J = 12.8 Hz, 2H), 3.96 (d, J = 6.2 Hz, 2H), 3.88 (dd, J = 10.0, 3.4 Hz, 1H), 3.76 (s, 3H), 3.47 (t, J = 5.8 Hz, 2H), 3.34 (s, 3H), 3.29 (t, J = 6.3 Hz, 2H), 3.01 (tdd, J = 12.4, 5.5, 2.8 Hz, 2H), 1.96 - 1.86 (m, 1H), 1.85–1.74 (m, 4H), 1.47–1.31 (m, 2H), 0.88 (s, 9H), 0.06 (s, 3H), 0.03 (s, 3H).

[1018] O - Acetyl - N - (O - (tert - butyldimethylsilyl) - N - (2 - (4 - ((((3 - methoxypropyl)carbamoyl)oxy)methyl)piperidin - 1 - yl)thiazole - 4 - carbonyl) - L - seryl) - L - serine methyl ester (32.5)

[1019]

[1020] Using the procedure described in Example 15.6, O - (tert - butyldimethylsilyl) - N - (2 - (4 - ((((3 - methoxypropyl)carbamoyl)oxy)methyl)piperidin - 1 - yl)thiazole - 4 - carbonyl) - L - serine methyl ester (0.447 g, 0.780 mmole) was converted to O - acetyl - N - (O - (tert - butyldimethylsilyl) - N - (2 - (4 - ((((3 - methoxypropyl)carbamoyl)oxy)methyl)piperidin - 1 - yl)thiazole - 4 - carbonyl) - L - seryl) - L - serine methyl ester (0.366 g, 67%) as a pale yellow oil.

[1021] 11H NMR (400 MHz, CDCl3) δ 8.00 (d, J = 7.1 Hz, 1H), 7.43 (d, J = 7.8 Hz, 1H), 7.38 (s, 1H), 5.09 (s, 1H), 4.88 (dt, J = 7.7, 3.8 Hz, 1H), 4.58 (ddd, J = 7.2, 5.8, 3.6 Hz, 1H), 4.47 (dt, J = 11.4, 4.2 Hz, 1H), 4.31 (dd, J = 11.4, 3.7 Hz, 1H), 4.19 (ddd, J = 9.8, 3.6, 2.2 Hz, 1H), 4.02 (d, J = 12.9 Hz, 2H), 3.96 (d, J = 6.2 Hz, 2H), 3.76 (s, 3H), 3.75–3.70 (m, 1H), 3.47 (t, J = 5.8 Hz, 2H), 3.34 (s, 3H), 3.29 (t, J = 6.2 Hz, 2H), 3.00 (ddd, J = 15.5, 7.9, 3.2 Hz, 2H), 2.05 (s, 3H), 1.87 (d, J = 10.7 Hz, 1H), 1.85–1.73 (m, 4H), 1.47–1.32 (m, 2H), 0.93 (s, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[1022] Methyl 2-(2-(2-(4-((((3-methoxypropyl)carbamoyl)oxy)methyl)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (32)

[1023]

[1024] Using the procedure described for compound 15, O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((((3-methoxypropyl)carbamoyl)oxy)methyl)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.366 g, 0.521 mmol) was converted to methyl 2-(2-(2-(4-((((3-methoxypropyl)carbamoyl)oxy)methyl)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.098 g, 37%).

[1025] 11H NMR (400 MHz, CDCl3) δ 9.73 (s, 1H), 8.51 (s, 1H), 7.41 (s, 1H), 6.71 (d, J = 2.1 Hz, 1H), 6.66 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.43 (t, J = 1.8 Hz, 1H), 5.07 (s, 1H), 4.05 (dd, J = 13.0, 3.7 Hz, 2H), 3.97 (d, J = 6.2 Hz, 2H), 3.89 (s, 3H), 3.47 (t, J = 5.8 Hz, 2H), 3.34 (s, 3H), 3.30 (q, J = 6.2 Hz, 2H), 3.03 (td, J = 12.7, 2.8 Hz, 2H), 1.90 (d, J = 6.3 Hz, 1H), 1.84 (d, J = 13.3 Hz, 2H), 1.79 (q, J = 6.2 Hz, 2H), 1.47–1.32 (m, 2H).

[1026] Compound 33: Methyl 2-(2-(2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carbox amido)acrylamido)acrylate

[1027] Ethyl 2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (33.1)

[1028]

[1029] Using the procedure described in Example 27.2, ethyl 2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (Example 12.1, 0.956 g, 2.69 mmole) was converted to ethyl 2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate as a white solid (0.512 g, 53%).

[1030] 1 1H NMR (400 MHz, CDCl3) δ 7.44 (s, 1H), 4.76 (d, J = 7.5 Hz, 1H), 4.35 (q, J = 7.1 Hz, 2H), 4.23 (t, J = 4.5 Hz, 2H), 4.04–3.94 (m, 2H), 3.73 (td, J = 10.9, 9.2, 5.1 Hz, 1H), 3.62–3.55 (m, 2H), 3.40 (s, 3H), 3.17 (ddd, J = 13.3, 11.5, 3.0 Hz, 2H), 2.06 (ddt, J = 12.6, 5.0, 2.3 Hz, 2H), 1.51 (dtd, J = 12.8, 11.2, 4.3 Hz, 2H), 1.37 (t, J = 7.1 Hz, 3H).

[1031] O-(tert-Butyldimethylsilyl)-N-(2-(4-(((2-Methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (33.2)

[1032]

[1033] Using the procedure described in Example 19.3, ethyl 2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (0.512 g, 1.43 mmol) was converted to O-(tert-butyldimethylsilyl)-N-(2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.398 g, 51%) as a colorless oil.

[1034] 1 H NMR (400 MHz, CDCl3) δ 7.95 (d, J = 8.8 Hz, 1H), 7.38 (s, 1H), 4.82–4.74 (m, 2H), 4.27–4.20 (m, 2H), 4.20–4.14 (m, 1H), 4.00–3.91 (m, 2H), 3.88 (dd, J = 10.0, 3.4 Hz, 1H), 3.76 (s, 4H), 3.63–3.55 (m, 2H), 3.40 (s, 3H), 3.15 (ddd d, J = 13.3, 11.5, 7.2, 3.0 Hz, 2H), 2.09–2.00 (m, 2H), 1.59–1.45 (m, 2H), 0.88 (s, 9H), 0.05 (s, 3H), 0.03 (s, 3H).

[1035] O-Acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (33.3)

[1036]

[1037] Using the procedure described in Example 15.6, O-(tert-butyldimethylsilyl)-N-(2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.398 g, 0.731 mmol e) was converted to O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.366 g, 74%) as a pale yellow oil.

[1038] 1 1H NMR (400 MHz, CDCl3) δ 7.98 (d, J = 7.1 Hz, 1H), 7.43 (d, J = 7.8 Hz, 1H), 7.39 (s, 1H), 4.87 (dt, J = 7.7, 3.8 Hz, 1H), 4.77 (d, J = 7.8 Hz, 1H), 4.63–4.54 (m, 1H), 4.47 (ddd, J = 11.3, 9.5, 4.0 Hz, 1H), 4.31 (dd, J = 11.4, 3.7 Hz, 1H), 4.27–4.21 (m, 2H), 4.21–4.17 (m, 1H), 3.94 (d, J = 10.4 Hz, 2H), 3.80–3.69 (m, 2H), 3.76 (s, 3H), 3.59 (dd, J = 5.5, 3.6 Hz, 2H), 3.40 (s, 3H), 3.22–3.09 (m, 2H), 2.11–2.05 (m, 2H), 2.05 (s, 3H), 1.50 (dd, J = 14.1, 9.5 Hz, 2H), 0.92 (s, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[1039] Methyl 2-(2-(2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (33)

[1040]

[1041] Using the procedure described for compound 15, O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.366 g, 0.543 mmole) was converted to methyl 2-(2-(2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate as a white solid (0.124 g, 47%).

[1042] 11H NMR (400 MHz, CDCl3) δ 9.71 (s, 1H), 8.51 (s, 1H), 7.43 (s, 1H), 6.71 (d, J = 2.1 Hz, 1H), 6.66 (s, 1H), 6.00 (d, J = 1.3 Hz, 1H), 5.43 (t, J = 1.9 Hz, 1H), 4.78 (d, J = 7.8 Hz, 1H), 4.24 (t, J = 4.6 Hz, 2H), 3.98 (dt, J = 13.6, 3.9 Hz, 2H), 3.89 (s, 3H), 3.83–3.69 (m, 1H), 3.64–3.56 (m, 2H), 3.40 (s, 3H), 3.18 (ddd, J = 13.2, 11.5, 3.0 Hz, 2H), 2.15–2.05 (m, 2H), 1.53 (dtd, J = 12.8, 11.1, 4.3 Hz, 2H).

[1043] Compound 34: Methyl 2-(2-(2-(4-(2-(2-methoxyethoxy)acetamido)piperidin-1-yl)thiazole-4-carbox amido)acrylamido)acrylate

[1044] (2-(4-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (34.1)

[1045]

[1046] Ethyl 2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carboxylate (Example 12.1, 1.526 g, 4.29 mmol) was dissolved in 4 / 1 / 1 THF / methanol / water (8 mL). Lithium hydroxide monohydrate (0.356 g, 8.48 mmol) was added and the mixture was stirred at room temperature for 4 h. Water (25 mL) was added and the solution was treated with 1 N hydrochloric acid to pH = 4. The mixture was extracted with ethyl acetate (3 x 15 mL) and the combined organics were dried over magnesium sulfate, filtered and concentrated. The residue was suspended in DCM (8 mL). L-Serine methyl ester hydrochloride (0.795 g, 5.11 mmol) was added followed by N,N-diisopropylethylamine (1.50 mL, 8.61 mmol) and pyBOP (2.673 g, 5.14 mmol). The resulting solution was stirred at room temperature for 18 h and water (25 mL) was added. The two layers were separated and the aqueous layer was extracted with DCM (3 x 10 mL). The combined organics were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford (2-(4-((tert-butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester as a white solid (1.648 g, 90%). 11H NMR (400 MHz, CDCl3) δ 7.99 (d, J = 7.5 Hz, 1H), 7.38 (s, 1H), 4.79 (dt, J = 7.6, 3.8 Hz, 1H), 4.59 (d, J = 7.9 Hz, 1H), 4.08–3.99 (m, 2H), 3.94 (ddd, J = 13.0, 5.5, 2.9 Hz, 2H), 3.81 (s, 3H), 3.65 (d, J = 25.0 Hz, 1H), 3.13 (ddt, J = 13.6, 11.2, 2.6 Hz, 2H), 2.04 (dd, J = 12.9, 3.7 Hz, 2H), 1.57–1.47 (m, 2H), 1.46 (s, 9H).

[1047] O-(tert-Butyldimethylsilyl)-N-(2-(4-(2-(2-Methoxyethoxy)acetamido)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (34.2)

[1048]

[1049] Dissolve (2-(4-((tert-Butoxycarbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.506 g, 1.18 mmole) in DCM (2.5 mL). Add HCl (4 M solution in 1,4-dioxane, 1.20 mL, 4.80 mmole), and stir the mixture at room temperature for 5 h, then concentrate. Add a solution of 2-(2-Methoxyethoxy)acetic acid (0.192 g, 1.43 mmole) in DCM (2.5 mL) then add N,N-Diisopropylethylamine (0.410 mL, 2.35 mmole), HOBt.H2O (0.221 g, 1.44 mmole) and EDC.HCl (0.267 g, 1.39 mmole). Stir the mixture at room temperature for 2 1 / 2 days and add water (25 mL). Extract the mixture with DCM (3 x 10 mL), and dry the combined organic layers over magnesium sulfate, filter, and concentrate. Dissolve the residue in DCM (2.5 mL), and add imidazole (0.088 g, 1.29 mmol) and tert-butyldimethylchlorosilane (0.192 g, 1.27 mmol). Stir the mixture at room temperature for 18 h and add water (25 mL). Extract the mixture with DCM (3 x 10 mL), and dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford O-(tert-butyldimethylsilyl)-N-(2-(4-(2-(2-methoxyethoxy)acetamido)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.361 g, 55%).

[1050] 1 H NMR (400 MHz, CDCl3) δ 7.96 (d, J = 8.8 Hz, 1H), 7.39 (s, 1H), 7.13 (d, J = 8.0 Hz, 1H), 4.78 (ddd, J = 8.8, 3.4, 2.6 Hz, 1H), 4.16 (dd, J = 10.0, 2.6 Hz, 1H), 4.12–4.03 (m, 1H), 4.00 (s, 3H), 3.97–3.91 (m, 1H), 3.88 (dd, J = 10.0, 3.4 Hz, 1H), 3.76 (s, 3H), 3.71–3.64 (m, 2H), 3.59–3.52 (m, 2H), 3.39 (s, 3H), 3.18 (dddd, J = 13.2, 11.7, 8.7, 3.0 Hz, 2H), 2.09–1.98 (m, 2H), 1.68–1.51 (m, 2H), 0.88 (s, 9H), 0.05 (s, 3H), 0.03 (s, 3H).

[1051] O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-(2-(2-methoxyethoxy)acetamido)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (34.3)

[1052]

[1053] Using the procedure described in Example 15.6, O-(tert-butyldimethylsilyl)-N-(2-(4-(2-(2-methoxyethoxy)acetamido)piperidin-1-yl)thiazole-4-carbonyl)-L-serine methyl ester (0.361 g, 0.646 mmol) was converted to O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-(2-(2-methoxyethoxy)acetamido)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.267 g, 60%) as a colorless gel.

[1054] 1 H NMR (400 MHz, CDCl3) δ 7.99 (d, J = 7.1 Hz, 1H), 7.44 (d, J = 7.8 Hz, 1H), 7.40 (d, J = 2.6 Hz, 1H), 7.13 (d, J = 8.0 Hz, 1H), 4.87 (dq, J = 8.3, 4.2 Hz, 1H), 4.58 (tdd, J = 7.0, 3.6, 2.1 Hz, 1H), 4.47 (ddd, J = 11.4, 9.0, 4.0 Hz, 1H), 4.31 (dd, J = 11.4, 3.7 Hz, 1H), 4.19 (ddd, J = 9.8, 3.6, 1.2 Hz, 1H), 4.09–4.02 (m, 1H), 4.02–3.91 (m, 2H), 3.99 (s, 2H), 3.76 (s, 3H), 3.75–3.71 (m, 1H), 3.71–3.65 (m, 2H), 3.60–3.51 (m, 2H), 3.39 (s, 3H), 3.18 (dddd, J = 13.0, 11.5, 4.7, 2.9 Hz, 2H), 2.09–2.03 (m, 2H), 2.02 (s, 3H), 1.63–1.51 (m, 2H), 0.92 (d, J = 1.0 Hz, 9H), 0.14 (s, 3H), 0.13 (s, 3H).

[1055] Methyl 2-(2-(2-(4-(2-(2-methoxyethoxy)acetamido)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (34)

[1056]

[1057] Using the procedure described for Compound 15, O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.366 g, 0.543 mmol) was converted to methyl 2-(2-(2-(4-(((2-methoxyethoxy)carbonyl)amino)piperidin-1-yl)thiazole-4-carboxamido)acrylamido)acrylate (0.124 g, 47%) as a white solid. 1 H NMR (400 MHz, CDCl3) δ 9.72 (s, 1H), 8.51 (s, 1H), 7.43 (s, 1H), 7.13 (d, J = 8.0 Hz, 1H), 6.72 (d, J = 2.1 Hz, 1H), 6.66 (s, 1H), 6.01 (d, J = 1.3 Hz, 1H), 5.44 (t, J = 1.8 Hz, 1H), 4.13–4.04 (m, 1H), 4.04–3.94 (m, 2H), 3.99 (s, 2H), 3.89 (s, 3H), 3.71–3.63 (m, 2H), 3.59–3.51 (m, 2H), 3.39 (s, 3H), 3.27–3.15 (m, 2H), 2.12–2.01 (m, 2H), 1.63–1.51 (m, 2H).

[1058] Compound 35: Methyl 2-(2-(2-(4-((2-(2-methoxyethoxy)acetamido)methyl)phenyl)thiazole-4-carbox amido)acrylamido)acrylate

[1059] (4-Cyanobenzyl)carbamic acid tert-butyl ester (35.1)

[1060]

[1061] 4-(Aminomethyl)benzonitrile hydrochloride (3.013 g, 17.9 mmol) was suspended in DCM (36 mL). Di-tert-butyl dicarbonate (4.100 g, 18.8 mmol) was added followed by N,N-diisopropylethylamine (6.20 mL, 35.6 mmol), and the mixture was stirred at room temperature for 18 h. Water (50 mL) was added and the layers were separated. The aqueous layer was extracted with DCM (2 x 15 mL), and the combined organics were dried over magnesium sulfate, filtered, and concentrated to afford (4-cyanobenzyl)carbamic acid tert-butyl ester (4.901 g) as a white solid.

[1062] 11H NMR (400 MHz, CDCl3): δ 7.66–7.58 (m, 2H), 7.39 (d, J = 8.2 Hz, 2H), 5.03 (s, 1H), 4.37 (d, J = 6.3 Hz, 2H), 1.46 (s, 9H).

[1063] tert-Butyl (4-thiocarbamoylbenzyl)carbamate (35.2)

[1064]

[1065] Dissolve tert-butyl (4-cyanobenzyl)carbamate (4.901 g, 21.1 mmole) in pyridine (21 mL). Add triethylamine (3.30 mL, 23.5 mmole) and ammonium sulfide (40% aqueous solution, 4.40 mL, 25.8 mmole), and heat the mixture at 50 °C for 4 1 / 2 h, then cool to room temperature and concentrate. Dissolve the residue in ethyl acetate (50 mL), and wash the mixture successively with 1 N hydrochloric acid (2 x 25 mL) and saturated aqueous sodium chloride (1 x 25 mL). Dry the organic layer over magnesium sulfate, filter, and concentrate to afford tert-butyl (4-thiocarbamoylbenzyl)carbamate (5.376 g) as a yellow solid.

[1066] 1H NMR (400 MHz, DMSO) δ 9.81 (s, 1H), 9.44 (s, 1H), 7.89–7.82 (m, 2H), 7.44 (q, J = 6.5 Hz, 1H), 7.25 (d, J = 8.3 Hz, 2H), 4.15 (d, J = 6.2 Hz, 2H), 1.39 (s, 9H).

[1067] Ethyl 2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carboxylate (35.3)

[1068]

[1069] Dissolve tert-butyl (4-thiocarbamoylbenzyl)carbamate (5.376 g, 20.1 mmol) in ethanol (40 mL). Add ethyl bromopyruvate (2.80 mL, 22.3 mmol) and heat the mixture at 80 °C for 18 h, then cool to room temperature and concentrate. Suspend the residue in DCM (40 mL) and add triethylamine (5.70 mL, 40.7 mmol) and di-tert-butyl dicarbonate (4.857 g, 22.3 mmol). Stir the mixture at room temperature for 18 h and add water (100 mL). Separate the two layers and extract the aqueous layer with DCM (2 x 20 mL). Dry the combined organic layers over magnesium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography to afford ethyl 2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carboxylate (5.003 g, 69%) as an orange solid.

[1070] 1 H NMR (400 MHz, CDCl3): δ 8.14 (s, 1H), 8.01–7.92 (m, 2H), 7.36 (d, J = 8.2 Hz, 2H), 5.02 (d, J = 29.7 Hz, 1H), 4.45 (q, J = 7.1 Hz, 2H), 4.36 (d, J = 6.0 Hz, 2H), 1.46 (d, J = 3.8 Hz, 9H), 1.43 (t, J = 7.1 Hz, 3H).

[1071] (2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (35.4)

[1072]

[1073] Ethyl 2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carboxylate (5.003 g, 13.8 mmol) was dissolved in 4 / 1 / 1 THF / methanol / water (28 mL). Lithium hydroxide monohydrate (1.160 g, 27.6 mmol) was added, and the mixture was stirred at room temperature for 3 h. Water (50 mL) was added, and the solution was treated with 1 N hydrochloric acid to pH = 4. The mixture was extracted with ethyl acetate (3 x 15 mL), and the combined organic layers were dried over magnesium sulfate, filtered, and concentrated. The residue was suspended in DCM (28 mL), and L-serine methyl ester hydrochloride (2.589 g, 16.6 mmol) was added. N,N-Diisopropylethylamine (4.80 mL, 27.6 mmol), HOBt.H2O (2.554 g, 16.7 mmol), and EDC.HCl (3.187 g, 16.6 mmol) were added, and the mixture was stirred at room temperature for 18 h. Water (50 mL) was added and the two layers were separated. The aqueous layer was extracted with DCM (2 x 20 mL), and the combined organic layers were dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography to afford (2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (3.793 g, 63%) as a pale yellow solid.

[1074] 1 H NMR (400 MHz, CDCl3): δ 8.25 (d, J = 7.5 Hz, 1H), 8.09 (s, 1H), 7.93–7.85 (m, 2H), 7.35 (d, J = 7.9 Hz, 2H), 5.00 (s, 1H), 4.87 (dt, J = 7.5, 3.8 Hz, 1H), 4.36 (d, J = 6.0 Hz, 2H), 4.17–4.04 (m, 2H), 3.84 (s, 3H), 2.95 (t, J = 6.1 Hz, 1H), 1.48 (s, 9H).

[1075] O-(tert-Butyldimethylsilyl)-N-(2-(4-((2-(2-methoxyethoxy)acetamido)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (35.5)

[1076]

[1077] (2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.700 g, 1.61 mmol) was dissolved in DCM (3.2 mL). HCl (4 M solution in 1,4-dioxane, 1.60 mL, 6.40 mmol) was added and the mixture was stirred at room temperature for 2 h and then concentrated. The residue was suspended in DCM (3.2 mL) and 2-(2-methoxyethoxy)acetic acid (0.220 mL, 1.94 mmol) was added. N,N-Diisopropylethylamine (0.560 mL, 3.22 mmol), HOBt.H2O (0.297 g, 1.94 mmol) and EDC.HCl (0.377 g, 1.97 mmol) were added and the mixture was stirred at room temperature for 3 days. Water (25 mL) was added and the mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The residue was dissolved in DCM (3.2 mL) and imidazole (0.129 g, 1.89 mmol) and tert-butyldimethylchlorosilane (0.273, 1.81 mmol) were added. The mixture was stirred at room temperature for 18 h and water (25 mL) was added. The mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford O-(tert-butyldimethylsilyl)-N-(2-(4-((2-(2-methoxyethoxy)acetamido)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.838 g, 92%) as a colorless oil.

[1078] 1 H NMR (400 MHz, CDCl3): δ 8.22 (d, J = 8.7 Hz, 1H), 8.10 (s, 1H), 7.98–7.89 (m, 2H), 7.48 (s, 1H), 7.43–7.35 (m, 2H), 4.86 (dt, J = 8.7, 3.0 Hz, 1H), 4.54 (d, J = 5.9 Hz, 2H), 4.21 (dd, J = 10.1, 2.6 Hz, 1H), 4.08 (s, 2H), 3.95 (dd, J = 10.1, 3.4 Hz, 1H), 3.79 (s, 3H), 3.74–3.66 (m, 2H), 3.56–3.49 (m, 2H), 3.28 (s, 3H), 0.92 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[1079] O-Acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((2-(2-methoxyethoxy)acetamido)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (35.6)

[1080]

[1081] Dissolve O-(tert-butyldimethylsilyl)-N-(2-(4-((2-(2-methoxyethoxy)acetamido)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.838 g, 1.48 mmole) in 4 / 1 / 1 THF / methanol / water (3 mL). Add lithium hydroxide monohydrate (0.125 g, 2.98 mmole) and stir the mixture at room temperature for 2 hours. Add water (25 mL) and treat the solution with 1 N hydrochloric acid to pH = 4. Extract the mixture with ethyl acetate (3 x 10 mL) and dry, filter, and concentrate the combined organic layers over magnesium sulfate. Dissolve the residue in DCM (3 mL) and add L-serine methyl ester hydrochloride (0.282 g, 1.81 mmole). Add N,N-diisopropylethylamine (0.520 mL, 2.99 mmole), HOBt.H2O (0.277 g, 1.81 mmole), and EDC.HCl (0.343 g, 1.79 mmole) and stir the mixture at room temperature for 18 hours. Add water (25 mL) and extract the mixture with DCM (3 x 10 mL). Dry, filter, and concentrate the combined organic layers over magnesium sulfate. Dissolve the residue in DCM (3 mL) and add triethylamine (0.230 mL, 1.64 mmole) and acetic anhydride (0.155 mL, 1.64 mmole). Stir the mixture at room temperature for 5 hours and add water (25 mL). Extract the mixture with DCM (3 x 10 mL) and dry, filter, and concentrate the combined organic layers over magnesium sulfate. Purify the crude residue by silica gel chromatography to afford O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((2-(2-methoxyethoxy)acetamido)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.593 g, 58%) as a colorless oil.

[1082] 11H NMR (400 MHz, CDCl3): δ 8.29–8.22 (m, 1H), 8.11 (d, J = 2.4 Hz, 1H), 7.95 (dt, J = 8.5, 2.0 Hz, 2H), 7.48 (t, J = 6.4 Hz, 2H), 7.44–7.36 (m, 2H), 4.90 (tt, J = 7.4, 3.8 Hz, 1H), 4.71–4.63 (m, 1H), 4.54 (d, J = 6.0 Hz, 2H), 4.49 (ddd, J = 11.0, 7.1, 3.9 Hz, 1H), 4.34 (dd, J = 11.4, 3.6 Hz, 1H), 4.23 (dt, J = 9.9, 3.4 Hz, 1H), 4.09 (d, J = 4.9 Hz, 2H), 3.85–3.80 (m, 1H), 3.77 (d, J = 4.2 Hz, 3H), 3.73–3.66 (m, 2H), 3.57–3.49 (m, 2H), 3.28 (s, 3H), 2.01 (s, 3H), 0.96 (s, 9H), 0.19–0.12 (m, 6H).

[1083] Methyl 2-(2-(2-(4-((2-(2-Methoxyethoxy)ethylcarbamoyl)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (35)

[1084]

[1085] O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((2-(2-methoxyethoxy)ethylamino)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.593 g, 0.853 mmol) was dissolved in THF (3.2 mL), and TBAF (1 M solution in THF, 2.10 mL, 2.10 mmol) was added. The solution was stirred at room temperature for 90 minutes and water (25 mL) was added. The mixture was extracted with ethyl acetate (3 x 10 mL), and the combined organic layers were dried over magnesium sulfate, filtered and concentrated. The residue was dissolved in DCM (3.2 mL) and cooled to 0 °C. Triethylamine (0.180 mL, 1.28 mmol) and methanesulfonyl chloride (0.099 mL, 1.28 mmol) were added, and the mixture was stirred at 0 °C for 60 minutes. Water (25 mL) was added, and the mixture was extracted with DCM (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The residue was dissolved in THF (3.2 mL) and cooled to 0 °C. DBU (0.180 mL, 1.20 mmol) was added, and the mixture was stirred at 0 °C for 90 minutes. Water (25 mL) was added, and the mixture was extracted with ethyl acetate (3 x 10 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography to afford methyl 2-(2-(2-(4-((2-(2-methoxyethoxy)ethylamino)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (0.180 g, 42%) as a white solid.

[1086] 1 H NMR (400 MHz, CDCl3): δ 10.02 (s, 1H), 8.55 (s, 1H), 8.15 (s, 1H), 8.04–7.94 (m, 2H), 7.48 (s, 1H), 7.44–7.38 (m, 2H), 6.79 (d, J = 2.2 Hz, 1H), 6.71 (s, 1H), 6.04 (d, J = 1.3 Hz, 1H), 5.51 (t, J = 1.9 Hz, 1H), 4.54 (d, J = 6.0 Hz, 2H), 4.08 (s, 2H), 3.91 (s, 3H), 3.74–3.67 (m, 2H), 3.59–3.50 (m, 2H), 3.28 (s, 3H).

[1087] Compound 36: Methyl 2-(2-(2-(4-((tetrahydro-2H-pyran-4-carboxamido)methyl)phenyl)thiazole-4-carboxamide amido)acrylamido)acrylate

[1088] O-(tert-Butyldimethylsilyl)-N-(2-(4-((tetrahydro-2H-pyran-4-carboxamido)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (36.1)

[1089]

[1090] Dissolve (2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (Example 35.4, 0.603 g, 1.38 mmol) in DCM (2.8 mL). Add HCl (4 M solution in 1,4-dioxane), and stir the mixture at room temperature for 2 h, then concentrate. Suspend the residue in DCM (2.8 mL), and add tetrahydro-2H-pyran-4-carboxylic acid (0.218 g, 1.40 mmol). Add N,N-diisopropylethylamine (0.480 mL, 2.76 mmol), HOBt.H2O (0.256 g, 1.67 mmol) and EDC.HCl (0.324 g, 1.69 mmol), and stir the mixture at room temperature for 18 h. Add water (25 mL), and extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter and concentrate. Dissolve the residue in DCM (5.6 mL), and add imidazole (0.112 g, 1.65 mmol) and tert-butyldimethylchlorosilane (0.237 g, 1.57 mmol). Stir the mixture at room temperature for 5 h and add water (25 mL). Extract the mixture with DCM (3 x 10 mL), and dry the combined organic layers over magnesium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography to afford O-(tert-butyldimethylsilyl)-N-(2-(4-((tetrahydro-2H-pyran-4-carboxamido)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester as a pale yellow solid (0.535 g, 69%).

[1091] 11H NMR (400 MHz, CDCl3): δ 8.22 (d, J = 8.6 Hz, 1H), 8.08 (s, 1H), 7.96–7.88 (m, 2H), 7.38–7.31 (m, 2H), 5.94 (s, 1H), 4.89–4.80 (m, 1H), 4.51 (d, J = 5.8 Hz, 2H), 4.21 (dd, J = 10.1, 2.6 Hz, 1H), 4.03 (ddd, J = 11.5, 4.0, 2.2 Hz, 2H), 3.95 (dd, J = 10.1, 3.4 Hz, 1H), 3.79 (s, 3H), 3.43 (td, J = 11.4, 2.9 Hz, 2H), 2.42 (tt, J = 11.1, 4.5 Hz, 1H), 1.94–1.74 (m, 4H), 0.92 (s, 9H), 0.07 (s, 3H), 0.06 (s, 3H).

[1092] O - Acetyl - N - (O - (tert - butyldimethylsilyl) - N - (2 - (4 - ((tetrahydro - 2H - pyran - 4 - carboxamido)methyl)phenyl)thiazole - 4 - carbonyl) - L - seryl) - L - serine methyl ester (36.2)

[1093]

[1094] Dissolve O-(tert-butyldimethylsilyl)-N-(2-(4-((tetrahydro-2H-pyran-4-carboxamido)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.535 g, 0.952 mmol) in 4 / 1 / 1 THF / methanol / water (2 mL). Add lithium hydroxide monohydrate (0.063 g, 1.60 mmol), and stir the mixture at room temperature for 3 h. Add water (25 mL), and treat the solution with 1 N hydrochloric acid to pH = 4. Extract the mixture with ethyl acetate (3 x 10 mL), and dry, filter, and concentrate the combined organic layers over magnesium sulfate. Dissolve the residue in DCM (4 mL), and add L-serine methyl ester hydrochloride (0.182 g, 1.17 mmol). Add N,N-diisopropylethylamine (0.340 mL, 1.95 mmol), HOBt.H2O (0.175 g, 1.14 mmol), and EDC.HCl (0.223 g, 1.16 mmol), and stir the mixture at room temperature for 3 days. Add water (25 mL), and extract the mixture with DCM (3 x 10 mL). Dry, filter, and concentrate the combined organic layers over magnesium sulfate. Dissolve the residue in DCM (4 mL), and add triethylamine (0.150 mL, 1.07 mmol) and acetic anhydride (0.099 mL, 1.09 mmol). Stir the mixture at room temperature for 3 h and add water (25 mL). Extract the mixture with DCM (3 x 10 mL), and dry, filter, and concentrate the combined organic layers over magnesium sulfate. Purify the crude residue by silica gel chromatography to afford O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((tetrahydro-2H-pyran-4-carboxamido)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.441 g, 88%) as a colorless oil.

[1095] 11H NMR (400 MHz, CDCl3): δ 8.26 (d, J = 7.0 Hz, 1H), 8.10 (d, J = 2.4 Hz, 1H), 7.97–7.90 (m, 2H), 7.48 (d, J = 7.8 Hz, 1H), 7.38–7.30 (m, 2H), 5.90 (t, J = 5.9 Hz, 1H), 4.90 (dq, J = 7.0, 3.5 Hz, 1H), 4.66 (td, J = 7.3, 3.7 Hz, 1H), 4.51 (d, J = 5.8 Hz, 2H), 4.47 (dd, J = 6.7, 4.0 Hz, 1H), 4.34 (dd, J = 11.4, 3.6 Hz, 1H), 4.23 (dd, J = 9.8, 3.7 Hz, 1H), 4.04 (ddd, J = 11.5, 4.2, 2.3 Hz, 2H), 3.84–3.79 (m, 1H), 3.77 (s, 3H), 3.43 (td, J = 11.5, 2.9 Hz, 2H), 2.42 (tt, J = 11.0, 4.4 Hz, 1H), 2.01 (s, 3H), 1.92–1.75 (m, 4H), 0.96 (s, 9H), 0.17 (s, 3H), 0.16 (s, 3H).

[1096] Methyl 2-(2-(2-(4-((tetrahydro-2H-pyran-4-ylcarbonyl)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (36)

[1097]

[1098] Dissolve O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((tetrahydro-2H-pyran-4-carboxamido)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.441 g, 0.638 mmol) in THF (1.3 mL), and add TBAF (1 M solution in THF, 1.60 mL, 1.60 mmol). Stir the mixture at room temperature for 2 h and add water (25 mL). Extract the mixture with ethyl acetate (3 x 10 mL), and dry, filter, and concentrate the combined organic layers over magnesium sulfate. Dissolve the residue in DCM (2.6 mL) and cool to 0 °C. Add triethylamine (0.135 mL, 0.963 mmol) and methanesulfonyl chloride (0.075 mL, 0.969 mmol), and stir the mixture at 0 °C for 60 min. Add water (25 mL), and extract the mixture with DCM (3 x 10 mL). Dry, filter, and concentrate the combined organic layers over magnesium sulfate. Dissolve the residue in THF (2.6 mL) and cool to 0 °C. Add DBU (0.150 mL, 1.00 mmol), and stir the mixture at 0 °C for 45 min. Add water (25 mL), and extract the mixture with ethyl acetate (3 x 10 mL). Filter the combined organic layers, then dry, filter, and concentrate over magnesium sulfate. Suspend the residue in a small amount of ethyl acetate, and collect the solid by filtration. Combine the two batches of harvests to afford methyl 2-(2-(2-(4-((tetrahydro-2H-pyran-4-carboxamido)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (0.101 g, 32%) as a white solid.

[1099] 1 H NMR (400 MHz, CDCl3): δ 10.01 (s, 1H), 8.56 (s, 1H), 8.14 (s, 1H), 8.02–7.92 (m, 2H), 7.36 (d, J = 8.0 Hz, 2H), 6.78 (d, J = 2.2 Hz, 1H), 6.70 (s, 1H), 6.04 (d, J = 1.3 Hz, 1H), 5.85 (s, 1H), 5.51 (t, J = 1.9 Hz, 1H), 4.52 (d, J = 5.8 Hz, 2H), 4.04 (ddd, J = 11.6, 4.3, 2.4 Hz, 2H), 3.91 (s, 3H), 3.43 (td, J = 11.4, 3.0 Hz, 2H), 2.41 (tt, J = 11.0, 4.6 Hz, 1H), 1.93–1.74 (m, 4H).

[1100] Compound 37: Methyl 2-(2-(2-(4-((6-chlorohexanamido)methyl)phenyl)thiazole-4-carboxamido)acrylamido acrylate

[1101] O-(tert-Butyldimethylsilyl)-N-(2-(4-((6-chlorohexanamido)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (37.1)

[1102]

[1103] Dissolve (2-(4-(((tert-butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (Example 35.4, 0.603 g, 1.38 mmol) in DCM (2.8 mL). Add HCl (4 M solution in 1,4-dioxane, 1.40 mL, 5.60 mmol), and stir the mixture at room temperature for 3 hours, then concentrate. Suspend the residue in DCM (2.8 mL), and add a solution of 6-chlorohexanoic acid (0.249 g, 1.65 mmol) in DCM (0.5 mL). Add N,N-diisopropylethylamine (0.480 mL, 2.76 mmol), HOBt·H2O (0.254 g, 1.66 mmol) and EDC·HCl (0.320 g, 1.67 mmol), and stir the mixture at room temperature for 3 days. Add water (25 mL), and extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter and concentrate. Dissolve the residue in DCM (2.8 mL), and add imidazole (0.114 g, 1.67 mmol) and tert-butyldimethylchlorosilane (0.231 g, 1.53 mmol). Stir the mixture at room temperature for 3 hours and add water (25 mL). Extract the mixture with DCM (3 x 10 mL), and dry the combined organic layers over magnesium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography to afford O-(tert-butyldimethylsilyl)-N-(2-(4-((6-chlorohexanamido)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester as a white solid (0.612 g, 76%).

[1104] 11H NMR (400 MHz, CDCl3): δ 8.21 (d, J = 8.6 Hz, 1H), 8.07 (s, 1H), 7.95–7.89 (m, 2H), 7.39–7.31 (m, 2H), 5.93 (t, J = 6.0 Hz, 1H), 4.89–4.81 (m, 1H), 4.50 (d, J = 5.8 Hz, 2H), 4.21 (dd, J = 10.1, 2.7 Hz, 1H), 3.95 (dd, J = 10.1, 3.4 Hz, 1H), 3.79 (s, 3H), 3.54 (t, J = 6.6 Hz, 2H), 2.28 (t, J = 7.5 Hz, 2H), 1.80 (dt, J = 8.1, 6.7 Hz, 2H), 1.73 (tt, J = 8.3, 6.4 Hz, 2H), 1.56–1.47 (m, 2H), 0.92 (s, 9H), 0.08 (s, 3H), 0.06 (s, 3H).

[1105] O-Acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((6-chlorohexanamido)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (37.2)

[1106]

[1107] Dissolve O-(tert-butyldimethylsilyl)-N-(2-(4-((6-chlorohexanamido)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (0.612 g, 1.05 mmol) in 4 / 1 / 1 THF / methanol / water (2 mL). Add lithium hydroxide monohydrate (0.065 g, 1.55 mmol), and stir the mixture at room temperature for 3 h. Add water (25 mL), and treat the solution with 1 N hydrochloric acid to pH = 4. Extract the mixture with ethyl acetate (3 x 10 mL), and dry, filter, and concentrate the combined organic layers over magnesium sulfate. Dissolve the residue in DCM (2 mL), and add L-serine methyl ester hydrochloride (0.192 g, 1.23 mmol). Add N,N-diisopropylethylamine (0.370 mL, 2.12 mmol), HOBt.H2O (0.199 g, 1.30 mmol), and EDC.HCl (0.240 g, 1.25 mmol), and stir the mixture at room temperature for 18 h. Add water (25 mL), and extract the mixture with DCM (3 x 10 mL). Dry, filter, and concentrate the combined organic layers over magnesium sulfate. Dissolve the residue in DCM (4 mL), and add triethylamine (0.165 mL, 1.18 mmol) and acetic anhydride (0.110 mL, 1.16 mmol). Stir the mixture at room temperature for 3 h and add water (25 mL). Extract the mixture with DCM (3 x 10 mL), and dry, filter, and concentrate the combined organic layers over magnesium sulfate. Purify the crude residue by silica gel chromatography to afford O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((6-chlorohexanamido)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.288 g, 39%) as a colorless oil.

[1108] 11H NMR (400 MHz, CDCl3): δ 8.26 (d, J = 7.2 Hz, 1H), 8.10 (d, J = 2.3 Hz, 1H), 7.98–7.88 (m, 2H), 7.47 (d, J = 7.8 Hz, 1H), 7.39–7.31 (m, 2H), 5.84 (t, J = 5.6 Hz, 1H), 4.90 (dt, J = 7.5, 3.7 Hz, 1H), 4.66 (td, J = 7.3, 3.7 Hz, 1H), 4.54–4.47 (m, 3H), 4.34 (dd, J = 11.4, 3.6 Hz, 1H), 4.22 (dt, J = 9.8, 3.4 Hz, 1H), 3.84–3.79 (m, 1H), 3.77 (d, J = 4.1 Hz, 3H), 3.55 (t, J = 6.6 Hz, 2H), 2.27 (t, J = 7.5 Hz, 2H), 2.05 (s, 3H), 1.86–1.77 (m, 2H), 1.77–1.66 (m, 2H), 1.56–1.48 (m, 2H), 0.96 (s, 9H), 0.16 (t, J = 4.8 Hz, 6H).

[1109] Methyl 2-(2-(2-((4-((6-chlorohexanamido)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (37)

[1110]

[1111] Dissolve O-acetyl-N-(O-(tert-butyldimethylsilyl)-N-(2-(4-((6-chlorohexanamido)methyl)phenyl)thiazole-4-carbonyl)-L-seryl)-L-serine methyl ester (0.288 g, 0.405 mmol) in THF (1.6 mL). Add TBAF (1 M solution in THF, 1.00 mL, 1.00 mmol), and stir the solution at room temperature for 2 h. Add water (25 mL), and extract the mixture with ethyl acetate (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Dissolve the residue in DCM (1.6 mL), and cool to 0 °C. Add triethylamine (0.086 mL, 0.614 mmol) and methanesulfonyl chloride (0.048 mL, 0.620 mmol), and stir the mixture at 0 °C for 45 min. Add water (25 mL), and extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Dissolve the residue in THF (1.6 mL), and cool to 0 °C. Add DBU (0.091 mL, 0.608 mmol), and stir the mixture at 0 °C for 30 min. Add water (25 mL), and extract the mixture with ethyl acetate (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter, and concentrate. Purify the crude residue by silica gel chromatography to afford methyl 2-(2-(2-(4-((6-chlorohexanamido)methyl)phenyl)thiazole-4-carboxamido)acrylamido)acrylate (0.100 g, 48%) as a white solid.

[1112] 1 H NMR (400 MHz, CDCl3): δ 10.03 (s, 1H), 8.58 (s, 1H), 8.15 (s, 1H), 8.04–7.94 (m, 2H), 7.44–7.34 (m, 2H), 6.80 (d, J = 2.3 Hz, 1H), 6.73 (s, 1H), 6.06 (d, J = 1.3 Hz, 1H), 5.86 (s, 1H), 5.53 (t, J = 1.9 Hz, 1H), 4.53 (d, J = 5.8 Hz, 2H), 3.93 (s, 3H), 3.57 (t, J = 6.6 Hz, 2H), 2.30 (t, J = 7.5 Hz, 2H), 1.90–1.79 (m, 2H), 1.75 (tt, J = 8.3, 6.4 Hz, 2H), 1.58–1.49 (m, 2H).

[1113] Compound 38: Methyl 2-(2-(2-(4-((3-((tert-butoxycarbonyl)amino)propanamido)methyl)phenyl)thiazole-4- carboxamido)acrylamido)acrylate

[1114] N-(2-(4-((3-((tert-Butoxycarbonyl)amino)propanamido)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (38.1)

[1115]

[1116] Dissolve (2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)thiazole-4-carbonyl)-L-serine methyl ester (Example 35.4, 0.612 g, 1.41 mmol) in DCM (5.6 mL). Add HCl (4 M solution in 1,4-dioxane, 1.40 mL, 5.60 mmol), and stir the mixture at room temperature for 3 h, then concentrate. Suspend the residue in DCM (5.6 mL), and add (tert-Butoxycarbonyl)-□-alanine (0.317 g, 1.68 mmol). Add N,N-Diisopropylethylamine (0.480 mL, 2.76 mmol), HOBt.H2O (0.260 g, 1.70 mmol) and EDC.HCl (0.320 g, 1.67 mmol), and stir the mixture at room temperature for 3 days. Add water (25 mL), and extract the mixture with DCM (3 x 10 mL). Dry the combined organic layers over magnesium sulfate, filter and concentrate. Dissolve the residue in DCM (5.6 mL), and add imidazole (0.112 g, 1.65 mmol) and tert-butyldimethylchlorosilane (0.231 g, 1.53 mmol). Stir the mixture at room temperature for 3 h and add water (25 mL). Extract the mixture with DCM (3 x 10 mL), and dry the combined organic layers over magnesium sulfate, filter and concentrate. Purify the crude residue by silica gel chromatography to afford N-(2-(4-((3-((tert-Butoxycarbonyl)amino)propanamido)methyl)phenyl)thiazole-4-carbonyl)-O-(tert-butyldimethylsilyl)-L-serine methyl ester (0.626 g, 72%) as a colorless solid.

[1117] 11H NMR (400 MHz, CDCl3): δ 8.21 (d, J = 8.7 Hz, 1H), 8.09 (s, 1H), 7.97–7.88 (m, 2H), 7.40–7.32 (m, 2H), 6.15 (s, 1H), 5.15 (s, 1H), 4.86 (dt, J = 8.7, 3.1 Hz, 1H), 4.50 (d, J = 5.8 Hz, 2H), 4.21 (dd, J = 10.0, 2.7 Hz, 1H), 3.95 (dd, J = 10.1, 3.4 Hz, 1H), 3.79 (s, 3H), 3.45 (q, J = 6.2 Hz, 2H), 2.49 (t, J = 6.0 Hz, 2H...

Claims

1. A compound of formula I or a pharmaceutically acceptable salt thereof: wherein R 1 is aryl, heteroaryl, cycloalkyl or heterocycle, said aryl, heteroaryl, cycloalkyl or heterocycle being optionally substituted by one or more selected from: alkyl, carboxyl, carbamate, urea, amide, amino, ether, ester and halo; and wherein when R 1 is pyridine or pyrazine, said pyridine or pyrazine is substituted by one or more selected from: alkyl, carboxyl, carbamate, urea, amide, amino, ether, ester and halo.

2. The compound according to claim 1, wherein the aryl, heteroaryl, cycloalkyl or heterocycle is substituted by one or more selected from: alkyl, carboxyl, carbamate, urea, amide, amino, ether, ester and halo.

3. The compound according to claim 1, wherein the aryl, heteroaryl, cycloalkyl or heterocycle is substituted by carbamate or amide.

4. The compound according to claim 1, wherein the aryl, heteroaryl, cycloalkyl or heterocycle is substituted by alkyl carbamate.

5. The compound of formula I or a pharmaceutically acceptable salt thereof according to claim 1, wherein R 1 is a group having the following structure: wherein: n is 0, 1, 2 or 3; m is 0, 1 or 2; X does not exist or is O, NR 3 or CH2; Y is absent or is O, NR 3 or CH2; Z 1 and Z 2 each independently is O, N or C; R 2 is an alkyl group (e.g., having 1 - 8 carbon atoms, straight-chain or branched-chain), wherein said alkyl group is optionally substituted (e.g., substituted by halogen, amino, ether, alkoxy or carbamate), or a heterocycle; and R 3 is H or an alkyl group (e.g., having 1 - 8 carbon atoms, straight-chain or branched-chain), wherein * represents the connection of the groups in the compound of formula I.

6. The compound according to claim 5, wherein Z 1 and Z 2 are each independently N or C.

7. The compound of formula I or a pharmaceutically acceptable salt thereof according to claim 1 or claim 5, wherein the compound is selected from:

8. The compound of formula I or a pharmaceutically acceptable salt thereof according to claim 1 or claim 5, wherein the compound is selected from:

9. The compound or its pharmaceutically acceptable salt according to claim 1 or claim 5, wherein R 1 is a group having the following structure: wherein: n is 0, 1, 2 or 3; m is 0, 1 or 2; X is O or CH2; and R 2 is an alkyl group (e.g., having 1 - 8 carbon atoms, straight-chain or branched-chain), wherein the alkyl group is optionally substituted (e.g., substituted by halogen, amino, ether, alkoxy or carbamate), or a heterocycle; and wherein * represents the connection of the groups in the compound of formula I.

10. The compound or its pharmaceutically acceptable salt according to claim 1 or claim 5, wherein R 1 is a group having the following structure: wherein: n is 0, 1, 2 or 3; X is O or CH2; and R 2 is an alkyl group (e.g., having 1 - 8 carbon atoms, straight-chain or branched-chain), wherein said alkyl group is optionally substituted (e.g., substituted by halogen, amino, ether, alkoxy or carbamate), or a heterocycle; and wherein * represents the connection of the groups in the compound of formula I.

11. The compound or its pharmaceutically acceptable salt according to claim 1, 5 or 9, wherein the compound is selected from:

12. The compound or its pharmaceutically acceptable salt according to claim 1, 5, 9 or 10, wherein the compound is selected from:

13. The compound or its pharmaceutically acceptable salt according to claim 1, 5, 9 or 10, wherein the compound is selected from:

14. The compound or its pharmaceutically acceptable salt according to claim 1 or claim 5, wherein R 1 is a group having the following structure: wherein: n is 0, 1, 2 or 3; X is O or CH2; R 2 is an alkyl group (e.g., having 1 - 8 carbon atoms, straight-chain or branched-chain), wherein the alkyl group is optionally substituted (e.g., substituted by halogen, amino, ether, alkoxy or carbamate), or a heterocycle; and R 3 is H or an alkyl group (e.g., having 1 - 8 carbon atoms, straight-chain or branched-chain), wherein * represents the connection of the groups in the compound of formula I.

15. The compound or a pharmaceutically acceptable salt thereof according to claim 1, 5 or 14, wherein the compound is selected from:

16. The compound or a pharmaceutically acceptable salt thereof according to claim 1, 5 or 14, wherein the compound is selected from:

17. The compound or a pharmaceutically acceptable salt thereof according to claim 1 or 5, wherein the compound is selected from:

18. A pharmaceutical composition comprising the compound or a pharmaceutically acceptable salt thereof according to any one of claims 1-17.

19. The composition according to claim 18, wherein the composition is formulated for oral or parenteral (e.g., intravenous, intrapleural, intraperitoneal or intraovarian) administration.

20. The composition according to claim 18, wherein the composition is formulated for oral administration and is in the form of a capsule, cachet, lozenge or tablet.

21. The composition according to any one of claims 18-20, wherein the preparation is provided in unit dosage forms of 1 mg to 10 g of the compound, pharmaceutically acceptable salt or prodrug.

22. A method of treating cancer in a subject in need thereof, which comprises administering to the subject a therapeutically effective amount of the compound or a pharmaceutically acceptable salt thereof according to any one of claims 1-17.

23. The method according to claim 22, wherein the cancer has PRX3 expression.

24. The method according to claim 22 or claim 23, wherein the subject is a human subject.

25. The method according to claim 22 or claim 23, wherein the subject is a non-human animal subject (e.g., a non-human mammalian subject).

26. The method according to any one of claims 22-25, wherein the administration is effected by administering a pharmaceutical composition comprising the compound or a pharmaceutically acceptable salt thereof.

27. The method according to any one of claims 22-26, wherein the administration further comprises administering bortezomib, carboplatin, paclitaxel, an immunotherapeutic agent, or a combination thereof.

28. The method according to any one of claims 22-27, wherein the administration further comprises administering doxorubicin.

29. A method of inhibiting PRX3 in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound or a pharmaceutically acceptable salt according to any one of claims 1-17.

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