USRE48731E1

USRE48731E1 - Dihydronaphthyridines and related compounds useful as kinase inhibitors for the treatment of proliferative diseases

Info

Publication number: USRE48731E1
Application number: US16/387,315
Authority: US
Inventors: Daniel L. Flynn; Michael D. Kaufman; Peter A. Petillo
Original assignee: Deciphera Pharmaceuticals LLC
Current assignee: Deciphera Pharmaceuticals LLC
Priority date: 2012-06-07
Filing date: 2019-04-17
Publication date: 2021-09-14
Anticipated expiration: 2032-06-07

Abstract

The invention relates to dihydronaphthyridines and related compounds; compositions comprising an effective amount of a dihydronaphthyridine or a related compound; and methods for treating or preventing proliferative diseases comprising the administration of an effective amount of a dihydronaphthyridine or a related compound.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent application Ser. No. 13/491,394, filed on Jun. 7, 2012, entitled “DIHYDRONAPHTHYRIDINES AND RELATED COMPOUNDS USEFUL AS KINASE INHIBITORS FOR THE TREATMENT OF PROLIFERATIVE DISEASES,” which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

c-KIT (also known as KIT, CD117, and stem cell factor receptor) is a 145 kDa transmembrane tyrosine kinase protein that acts as a type-III receptor (Pereira et al. J. Carcin. 2005, 4, pg. 19). The c-KIT proto-oncogene, located on chromosome 4q11-21, encodes the c-KIT receptor, whose ligand is the stem cell factor (SCF, steel factor, kit ligand, mast cell growth factor, Morstyn, G. et al. Oncology 1994, 51 (2), pg. 205; Yarden, Y. et al. Embo. J. 1987, 6 (11), pg. 3341). The receptor has tyrosine-protein kinase activity and binding of the ligand SCF leads to the autophosphorylation of c-KIT and its association with substrates such as phosphatidylinositol 3-kinase (PI3K). Tyrosine phosphorylation by protein tyrosine kinases is of particular importance in cellular signaling and can mediate signals for major cellular processes, such as proliferation, survival, differentiation, apoptosis, attachment, invasiveness and migration. Defects in c-KIT are a cause of piebaldism, an autosomal dominant genetic developmental abnormality of pigmentation characterized by congenital patches of white skin and hair that lack melanocytes. Gain-of-function mutations of the c-KIT gene and the expression of constitutively phosphorylated c-KIT are found in most gastrointestinal stromal tumors GIST) and mastocytosis. Further, almost all gonadal seminomas/dysgerminomas exhibit c-KIT membranous staining, and several reports have clarified that some (10-25%) have a c-KIT gene mutation (Sakuma, Y. et al. Cancer Sci. 2004, 95 (9), pg. 716). c-KIT defects have also been associated with testicular tumors including germ cell tumors (GCT) and testicular germ cell tumors (TGCT).

The role of c-KIT expression has been studied in hematologic and solid tumors, such as acute leukemias (Cortes, J. et al. Cancer 2003, 97 (11), pg. 2760) and GIST (Fletcher, J. et al. Hum. Pathol. 2002, 33 (5), pg. 459). The clinical importance of c-KIT expression in malignant tumors relies on studies with Gleevec® (imatinib mesylate, STI571 (signal transduction inhibitor number 571), Novartis Pharma AG Basel, Switzerland) that specifically inhibits tyrosine kinase receptors (Lefevre, G. et al. J. Biol. Chem. 2004, 279 (30), pg. 31769). Moreover, a clinically relevant breakthrough has been the finding of anti-tumor effects of this compound in GIST, a group of tumors regarded as being generally resistant to conventional chemotherapy (de Silva, C. M.; Reid, R. Pathol. Oncol. Res. 2003, 9 (1), pp. 13-19). Most GISTs have primary activating mutations in the genes encoding the closely related RTKs c-KIT (75-80% of GIST) or PDGFRα (8% of the non-c-KIT mutated GIST). c-KIT and PDGFRα mutations are mutually exclusive in GIST (Rubin et al. Lancet 2007, 369, pg. 1731). The majority of primary GIST-causing c-KIT mutations affect the juxtamembrane (JM) region of the protein encoded by exon 11 (i.e. V560D) and consist of in-frame deletions or insertions, or missense mutations. c-KIT exon 11 mutations have been identified as primary mutations in approximately 75% of GISTs. Such JM domain mutations disrupt the autoinhibition mechanism of c-KIT kinase, leading to constitutive kinase activity and cell-transforming events causative of GIST (Chen, L. L. et al. Clin. Cancer Res. 2005, 11, pg. 3668-3677; Mol, C. D., et al. J. Biol. Chem. 2004, 279, pg. 31655-31663).

GIST most often become Gleevec® resistant, and molecularly targeted small molecule therapies that target c-KIT secondary mutations remain elusive. GIST patients who relapse after treatment with Gleevec® or Sutent® have disease still driven by c-KIT mutations. These secondary mutations occur on the same alleles as the primary JM-region mutation, and thus represent even more aggressive activated forms of c-KIT than the original primary mutation. These secondary mutants of c-KIT identified in GIST lead to acquired drug resistance. Secondary mutations are found in the extracellular domain of c-KIT (exon 9, i.e. AY501-502 duplication/insertion), ATP binding pocket (exon 13, i.e. K642E, V654A; exon 14, i.e. T670I), and activation loop (exon 17, i.e. N822K, D816H, D816V, D820A). These various secondary c-KIT mutations have been reported: Heinrich, M. C. et al. J. Clin. Oncol. 2006, 24, pg. 4764-4774; Debiec-Rychter, M., et al. Gastroenterology 2005, 128, pg. 270-279; Wardelmann, E., et al. Lancet Oncol. 2005, 6, pg. 249-251; Antonescu, C. R., et al. Clin. Cancer. Res. 2005, 11, pg. 4182-4190. Sunitinib malate (Sutent™, Pfizer) is an inhibitor of multiple RTKs, notably in this context, c-KIT and PDGFRα, and has been shown to be effective against certain imatinib-resistant c-KIT mutants, such as the ATP-binding pocket mutants V654A and T670I. Certain Gleevec®-resistant mutants are also resistant to sunitinib, such as D816H and D816V which are located in the activation loop of the c-KIT catalytic domain encoded by exon 17 (Corless et al. J. Clin. Oncol. 2004, 22, pg. 3813; Heinrich et al. J. Clin. Oncol. 2008, 26, pg. 5352; Gajiwala et al. Proc. Natl. Acad. Sci. USA 2009, 106:1542). Median survival after progression due to Gleevec®-resistance remains relatively short.

It has been demonstrated that complex, multiple secondary c-KIT mutations can arise and vary within individual patients, such variation in mutational status of c-KIT being demonstrated by biopsy samples obtained from different progressing metastases within each patient (Wardelmann, E., et al. Lancet Oncol. 2005, 6, pg. 249-251; Fletcher, J. A. and Rubin, B. P., Curr. Opin in Genetics & Develop., 2007, 17, pg. 3-7). This complex c-KIT mutational heterogeneity within individual patients underscores an unmet medical need to identify inhibitors of c-KIT kinase that are effective across a broad spectrum of c-KIT primary and secondary mutations. Such a broad spectrum c-KIT inhibitor would be of high therapeutic value in the treatment of refractory GIST patients.

SUMMARY OF THE INVENTION

The present invention discloses the unexpected utility of compounds that inhibit c-KIT kinase across a broad range of c-KIT mutations, including complex occurrences of primary mutations (KIT exon 9 or 11) and secondary KIT mutations (exons 13, 14, 17 and 18) that may arise in individual, refractory GIST patients. Also unexpected is the utility of compounds of the present invention to inhibit the problematic exon 17 D816V c-KIT mutation, for which there is currently no effective therapy. D816 mutations in c-KIT have been demonstrated to cause mastocytosis, mast cell leukemia, seminomas, dysgerminomas, lymphomas, and intracranial teratomas (Ning, A. Q, Li, J., and Arceci, R. J. Leuk Lymphoma, 2001, 41, pg. 513-522; Beghini, A , et al. Blood, 2000, 95, pg. 726-727; Tian, Q., et al. Am J. Pathol. 1999, 154, pg. 1643-1647; Nagata, H., et al. Proc. Natl. Acad. Sci. USA, 1995, 92, 10560-10564; Longley, B. J., et al. Nat. Genet., 1996, 12, pg. 312-314). The present invention also discloses new compounds for the treatment of diseases caused by c-KIT mutation, including new compounds for the treatment of refractory GIST, mast cell leukemia, or mastocytosis.

One aspect of the present invention provides a method of treating a disease caused by the kinase activity of c-KIT, oncogenic forms thereof, aberrant fusion proteins thereof or polymorphs thereof, comprising the administration of a compound of formula Ia

or a pharmaceutically acceptable salt thereof,
wherein:
A is selected from the group consisting of phenyl, naphthyl, and benzothienyl;
G1 is a heteroaryl taken from the group consisting of pyrrolyl, furyl, thienyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazinyl, pyridazinyl, triazinyl, pyridinyl, and pyrimidinyl;
G4 is a heterocyclyl taken from the group consisting of oxetanyl, azetadinyl, tetrahydrofuranyl, pyrrolidinyl, oxazolinyl, oxazolidinyl, imidazolonyl, pyranyl, tetrahydropyranyl, dioxalinyl, piperidinyl, and morpholinyl;
when A has one or more substitutable sp2-hybridized carbon atom, each respective sp2 hybridized carbon atom may be optionally substituted with a Z3 substituent;
Z1 is selected from the group consisting of —NH(R4), and —NHCOR8;
in the event that Z1 contains an alkyl or alkylene moiety, such moieties may be further substituted with one or more C1-C6alkyls;
each Z2 is independently and individually selected from the group consisting of hydrogen, C1-C6alkyl, C3-C8carbocyclyl, C1-C6 alkoxy, hydroxyl, hydroxyC1-C6alkyl-, cyano, (R3)₂N—, and —(CH₂)_nR5;
in the event that Z2 contains an alkyl or alkylene moiety, such moieties may be further substituted with one or more C1-C6alkyls;
each Z3 is independently and individually selected from the group consisting of H, methyl, ethyl, isopropyl, C3-C4 carbocyclyl, halogen, cyano, —(CH₂)_k—N(R3)₂, and —(CH₂)_k—R5;
R1 is selected from the group consisting of C1-C4alkyl, branched C3-C5alkyl, and C3-C5carbocyclyl;
each R2 is independently and individually selected from the group consisting of hydrogen, methyl, ethyl, halogen, fluoroalkyl wherein the alkyl moiety can be partially or fully fluorinated, cyano, and C2-C3alkynyl;
each R3 is independently and individually selected from the group consisting of H, C1-C6alkyl, branched C3-C7alkyl, and C3-C8carbocyclyl;
each R4 is independently and individually selected from the group consisting of H, C1-C6alkyl, hydroxyC2-C6alkyl, C1-C6alkoxyC2-C6alkyl, branched C3-C7alkyl, branched hydroxyC2-C6alkyl, branched C1-C6alkoxyC2-C6alkyl, —(CH₂)_q—N(R7)₂, —(CH₂)_q—R5, —(CH₂)_nC(O)R5, C3-C8carbocyclyl, hydroxyl substituted C3-C8carbocyclyl, alkoxy substituted C3-C8carbocyclyl, and —(CH₂)_n—R17;
each R5 is independently and individually selected from the group consisting of

and wherein the symbol (##) is the point of attachment of the R5 moiety;
each R5 may be optionally substituted with one or two R10 substituents;
each R7 is independently and individually selected from the group consisting of H, C1-C6alkyl, hydroxyC2-C6alkyl, C1-C6alkoxyC2-C6alkyl, branched C3-C7alkyl, branched hydroxyC2-C6 alkyl, branched C1-C6alkoxyC2-C6alkyl, —(CH₂)_q—R5, —(CH₂)_n—C(O)R5, —(CH₂)_n—C(O)OR3, C3-C8carbocyclyl, hydroxyl substituted C3-C8carbocyclyl, alkoxy substituted C3-C8carbocyclyl, and —(CH₂)_n—R17;
each R8 is independently and individually selected from the group consisting of hydrogen, C1-C6alkyl, branched C3-C7alkyl, fluoroalkyl wherein the alkyl moiety is partially or fully fluorinated, C3-C8carbocyclyl, Z3-substituted phenyl, Z3-substituted G1, Z3-substituted G1-C1-C6alkyl, Z2-substituted G4, Z2-substituted G4-C1-C6alkyl, C1-C6alkoxy, C1-C6alkoxyC1-C6alkyl, cyanoC1-C6alkyl, —N(R4)₂, and R5;
each R10 is independently and individually selected from the group consisting of CO₂H, CO₂C1-C6alkyl, CO—N(R4)₂, OH, C1-C6alkoxy, C1-C6alkyl, and —N(R4)₂;
each R17 is taken from the group comprising phenyl, naphthyl, pyrrolyl, furyl, thienyl, oxazolyl, thiazolyl, isoxazolyl, imidazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazinyl, pyridazinyl, triazinyl, oxetanyl, azetadinyl, tetrahydrofuranyl, oxazolinyl, oxazolidinyl, pyranyl, thiopyranyl, tetrahydropyranyl, dioxalinyl, pyrrolidinyl, and piperidinyl;
wherein R17 can be further substituted with one or more Z2 or Z3 moieties;
wherein two R3 or R4 moieties are independently and individually taken from the group consisting of C1-C6alkyl and branched C3-C6alkyl, hydroxyalkyl, and alkoxyalkyl and are attached to the same nitrogen atom, said moieties may cyclize to form a C3-C7 heterocyclyl ring;
and k is 1 or 2; n is 0-6; p is 1-4; q is 2-6; r is 0 or 1; t is 1-3.

In one embodiment, the invention provides a method of treating a disease caused by the kinase activity of c-KIT, oncogenic forms thereof, aberrant fusion proteins thereof or polymorphs thereof, wherein c-KIT contains a missense mutatation, insertion mutation, or a deletion mutation encoded by exons comprising Exon 9, Exon 11, Exon 13, Exon 14, Exon 17, or Exon 18, presenting either individually or in combination, comprising the administration of a compound of formula Ia or a pharmaceutically acceptable salt thereof.

A second aspect of the present invention provides a method of treating a disease selected from gastrointestinal stromal tumors, ovarian cancer, pancreatic cancer, prostate cancer, lung cancers, breast cancers, melanoma, renal cancers, hepatic cancers, cervical carcinomas, metastasis of primary tumor sites, papillary thyroid carcinoma, non-small cell lung cancer, mesothelioma, hypereosinophilic syndrome, colonic cancers, acute myeloid leukemia, germ cell tumors of the seminoma or dysgerminoma, teratomas, mastocytosis, or mast cell leukemia, said method comprising administering a therapeutically effective amount of a compound of Formula Ia, or a pharmaceutically acceptable salt thereof, to a patient.

A third aspect of the present invention provides a pharmaceutical composition comprising a compound of Formula Ia, or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier, with the proviso that the compound is not 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(naphthalen-1-yl)urea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(naphthalen-1-yl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(2,3-difluorophenyl)urea, 1-(2-fluoro-5-(1-isopropyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(naphthalen-1-yl)urea, 1-(4-chloro-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-phenylurea, 1-(4-chloro-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(naphthalen-1-yl)urea, 1-(4-chloro-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(3-cyanophenyl)urea, or 1-(4-chloro-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(2,3-difluorophenyl)urea.

A fourth aspect of the present invention provides use of a compound of Formula Ia or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for the treatment of a disease selected from gastrointestinal stromal tumors, ovarian cancer, pancreatic cancer, prostate cancer, lung cancers, breast cancers, melanoma, renal cancers, hepatic cancers, cervical carcinomas, metastasis of primary tumor sites, papillary thyroid carcinoma, non-small cell lung cancer, mesothelioma, hypereosinophilic syndrome, colonic cancers, acute myeloid leukemia, germ cell tumors of the seminoma or dysgerminoma, teratomas, mastocytosis, or mast cell leukemia.

A fifth aspect of the present invention provides a compound of formula Ia

and wherein the symbol (##) is the point of attachment of the R5 moiety;
each R5 may be optionally substituted with one or two R10 substituents;
each R7 is independently and individually selected from the group consisting of H, C1-C6alkyl, hydroxyC2-C6alkyl, C1-C6alkoxyC2-C6alkyl, branched C3-C7alkyl, branched hydroxyC2-C6 alkyl, branched C1-C6alkoxyC2-C6alkyl, —(CH₂)_q—R5, —(CH₂)_n—C(O)R5, —(CH₂)_n—C(O)OR3, C3-C8carbocyclyl, hydroxyl substituted C3-C8carbocyclyl, alkoxy substituted C3-C8carbocyclyl, and —(CH₂)_n—R17;
each R8 is independently and individually selected from the group consisting of hydrogen, C1-C6alkyl, branched C3-C7alkyl, fluoroalkyl wherein the alkyl moiety is partially or fully fluorinated, C3-C8carbocyclyl, Z3-substituted phenyl, Z3-substituted G1, Z3-substituted G1-C1-C6alkyl, Z2-substituted G4, Z2-substituted G4-C1-C6alkyl, C1-C6alkoxy, C1-C6alkoxyC1-C6alkyl, cyanoC1-C6alkyl, —N(R4)₂, and R5;
each R10 is independently and individually selected from the group consisting of CO₂H, CO₂C1-C6alkyl, CO—N(R4)₂, OH, C1-C6alkoxy, C1-C6alkyl, and —N(R4)₂;
each R17 is taken from the group comprising phenyl, naphthyl, pyrrolyl, furyl, thienyl, oxazolyl, thiazolyl, isoxazolyl, imidazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazinyl, pyridazinyl, triazinyl, oxetanyl, azetadinyl, tetrahydrofuranyl, oxazolinyl, oxazolidinyl, pyranyl, thiopyranyl, tetrahydropyranyl, dioxalinyl, pyrrolidinyl, and piperidinyl;
wherein R17 can be further substituted with one or more Z2 or Z3 moieties;
wherein two R3 or R4 moieties are independently and individually taken from the group consisting of C1-C6alkyl and branched C3-C6alkyl, hydroxyalkyl, and alkoxyalkyl and are attached to the same nitrogen atom, said moieties may cyclize to form a C3-C7 heterocyclyl ring;
and k is 1 or 2; n is 0-6; p is 1-4; q is 2-6; r is 0 or 1; t is 1-3;
with the proviso that the compound is not 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(naphthalen-1-yl)urea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(naphthalen-1-yl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(2,3-difluorophenyl)urea, 1-(2-fluoro-5-(1-isopropyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(naphthalen-1-yl)urea, 1-(4-chloro-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-phenylurea, 1-(4-chloro-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(naphthalen-1-yl)urea, 1-(4-chloro-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(3-cyanophenyl)urea, or 1-(4-chloro-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(2,3-difluorophenyl)urea.

In any of the foregoing aspects:

In one embodiment, the compound of Formula Ia is a compound wherein: A is phenyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: A is naphthyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: A is benzothienyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: R1 is taken from the group consisting of C1-C4alkyl, branched C3-C5alkyl, and C3-C5carbocyclyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: R1 is C1-C4alkyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: R1 is branched C3-C5alkyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: R1 is C3-C5carbocyclyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is selected from the group consisting of —NH(R4) and —NHCOR8; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NH(R4); or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NH(R4) and R4 is H or C1-C6 alkyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NH(R4) and R4 is H; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NH(R4) and R4 is C1-C6alkyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NH(R4) and R4 is methyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NR4COR8; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NHCOR8; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NHCOR8 and R8 is hydrogen, C1-C6alkyl, branched C3-C7alkyl, C3-C8carbocyclyl, —N(R4)2, or R5; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NHCOR8 and R8 is C1-C6alkyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NHCOR8 and R8 is branched C3-C7alkyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NHCOR8 and R8 is C3-C8carbocyclyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NHCOR8 and R8 is —N(R4)₂; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: Z1 is —NHCOR8 and R8 is R5; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound wherein: each R2 is independently hydrogen, methyl, or halogen and t is 2; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib

wherein:
R2 is hydrogen, methyl, or halogen; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: R2 is hydrogen; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: R2 is methyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: R2 is halogen; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is phenyl, R1 is C1-C4alkyl, branched C3-C5alkyl, or C3-C5carbocyclyl, R2 is hydrogen, methyl, or halogen, and Z1 is —NH(R4) or —NHCOR8; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is phenyl, R1 is C1-C4alkyl, R2 is methyl or halogen, and Z1 is —NH(R4) or —NHCOR8; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is phenyl, R1 is ethyl, R2 is methyl or halogen, and Z1 is —NH(R4) or —NHCOR8;

or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is phenyl, R1 is ethyl, R2 is methyl or halogen, Z1 is —NH(R4) and R4 is methyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is phenyl, R1 is ethyl, R2 is methyl, Z1 is —NH(R4) and R4 is methyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is phenyl, R1 is ethyl, R2 is halogen, Z1 is —NH(R4) and R4 is methyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is naphthyl, R1 is C1-C4alkyl, branched C3-C5alkyl, or C3-C5carbocyclyl, R2 is hydrogen, methyl, or halogen, and Z1 is —NH(R4) or —NHCOR8; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is naphthyl, R1 is C1-C4alkyl, R2 is methyl or halogen, and Z1 is —NH(R4) or —NHCOR8; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is naphthyl, R1 is ethyl, R2 is methyl or halogen, and Z1 is —NH(R4) or —NHCOR8; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is naphthyl, R1 is ethyl, R2 is methyl or halogen, Z1 is —NH(R4) and R4 is methyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is naphthyl, R1 is ethyl, R2 is methyl, Z1 is —NH(R4) and R4 is methyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is naphthyl, R1 is ethyl, R2 is halogen, Z1 is —NH(R4) and R4 is methyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is benzothienyl, R1 is C1-C4alkyl, branched C3-C5alkyl, or C3-C5carbocyclyl, R2 is hydrogen, methyl, or halogen, and Z1 is —NH(R4) or —NHCOR8; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is benzothienyl, R1 is C1-C4alkyl, R2 is methyl or halogen, and Z1 is —NH(R4) or —NHCOR8; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is benzothienyl, R1 is ethyl, R2 is methyl or halogen, and Z1 is —NH(R4) or —NHCOR8; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is benzothienyl, R1 is ethyl, R2 is methyl or halogen, Z1 is —NH(R4) and R4 is methyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is benzothienyl, R1 is ethyl, R2 is methyl, Z1 is —NH(R4) and R4 is methyl; or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula Ia is a compound of Formula Ib wherein: A is benzothienyl, R1 is ethyl, R2 is halogen, Z1 is —NH(R4) and R4 is methyl; or a pharmaceutically acceptable salt thereof.

In some embodiments, the present invention provides a method treating a disease caused by c-KIT kinase comprising gastrointestinal stromal tumors, ovarian cancer, melanoma, cervical carcinomas, acute myeloid leukemia, germ cell tumors of the seminoma or dysgerminoma, teratomas, mastocytosis, or mast cell leukemia, said method comprising administering to a patient a therapeutically effective amount of a compound selected from 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(naphthalen-1-yl)urea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(naphthalen-1-yl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(2,3-difluorophenyl)urea, 1-(2-fluoro-5-(1-isopropyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(naphthalen-1-yl)urea, 1-(4-chloro-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-phenylurea, 1-(4-chloro-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(naphthalen-1-yl)urea, 1-(4-chloro-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(3-cyanophenyl)urea, 1-(4-chloro-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(2,3-difluorophenyl)urea, 1-(4-chloro-3-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(3-cyanophenyl)urea, 1-(3-cyanophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)urea, 1-(benzo[b]thiophen-3-yl)-3-(2-fluoro-4-methyl-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)urea, 1-(benzo[b]thiophen-3-yl)-3-(2,4-difluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)urea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)-3-(3-fluorophenyl)urea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)-3-phenylurea, 1-(3-chlorophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)urea, 1-(3-cyanophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)urea, 1-(benzo[b]thiophen-3-yl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)urea, 1-(5-(7-amino-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-4-chloro-2-fluorophenyl)-3-(3-fluorophenyl)urea, 1-(5-(7-amino-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-4-chloro-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-2-fluoro-5-(1-isopropyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-phenylurea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-phenylurea, 1-[4-chloro-5-(1-ethyl-7-methylamino-2-oxo-1,2-dihydro-[1,6]naphthyridin-3-yl)-2-fluoro-phenyl]-3-(3-fluoro-phenyl)-urea, 1-[4-chloro-5-(1-ethyl-7-methylamino-2-oxo-1,2-dihydro-[1,6]naphthyridin-3-yl)-2-fluoro-phenyl]-3-(2-fluoro-phenyl)-urea, 1-(4-chloro-3-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea,

1-(4-chloro-5-(1-ethyl-7-(2-methoxyethylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(2-methoxyethylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-fluorophenyl)urea, 1-(4-chloro-5-(7-(2-(dimethylamino)ethylamino)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(7-(3-(dimethylamino)propylamino)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-bromo-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(benzo[b]thiophen-3-yl)-3-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2,4a,8a-tetrahydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)urea, 1-(4-chloro-3-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(2-methoxyethylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(4-fluorophenyl)urea, 1-(4-chloro-5-(1-ethyl-7-(2-methoxyethylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(2-fluorophenyl)urea, 1-(5-(1-ethyl-7-(2-methoxyethylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)-3-phenylurea, 1-(5-(1-ethyl-7-(2-methoxyethylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-phenylurea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(2-fluorophenyl)urea, 1-(4-chloro-5-(1-ethyl-7-(3-methoxypropylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(2,4-difluoro-5-(1-isopropyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(3-fluorophenyl)urea, 1-(2-fluoro-5-(1-isopropyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-4-methylphenyl)-3-(3-fluorophenyl)urea, 1-(4-chloro-5-(1-ethyl-2-oxo-7-(tetrahydro-2H-pyran-4-ylamino)-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, (S)-1-(4-chloro-5-(1-ethyl-7-(1-methoxypropan-2-ylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(3-fluorophenyl)urea, 1-(5-(7-(cyclopropylamino)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(3-fluorophenyl)urea,

1-(4-chloro-5-(1-ethyl-7-(1-methylpiperidin-4-ylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-2-oxo-7-(THF-3-ylamino)-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(2-(methylsulfonyl)ethylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(1-methylpyrrolidin-3-ylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-bromo-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-fluorophenyl)urea, 1-(4-bromo-5-(1-ethyl-7-(2-methoxyethylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-bromo-5-(1-ethyl-7-(2-(methylsulfonyl)ethylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(5-(7-acetamido-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-4-bromo-2-fluorophenyl)-3-phenylurea, 1-(5-(7-acetamido-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-4-chloro-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3,5-difluorophenyl)urea, 1-(4-bromo-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-phenylurea, 1-(5-(7-amino-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-4-bromo-2-fluorophenyl)-3-phenylurea, 1-(5-(7-amino-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(3-fluorophenyl)urea, 1-(benzo[b]thiophen-3-yl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)urea, 1-(3,5-difluorophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)urea, 1-(2,5-difluorophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)urea, 1-(2,5-difluorophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2,4a,8a-tetrahydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)urea, 1-(3,5-difluorophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2,4a,8a-tetrahydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)urea, N-(3-(2-bromo-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-2-cyanoacetamide, N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-2-cyanoacetamide, 1-(5-(7-acetamido-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)-3-phenylurea, N-(3-(2-chloro-5-(3-(3,5-difluorophenyl)ureido)-4-fluorophenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)acetamide, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(2,5-difluorophenyl)urea, 1-(3-chloro-5-fluorophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)urea, 3-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-chloro-5-fluorophenyl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-fluoro-5-methylphenyl)urea, methyl (3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)carbamate, N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-2-methoxyacetamide, 2-cyano-N-(3-(2,4-difluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)acetamide, 1-(4-cyano-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-2-fluoro-5-(1-isopropyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(3-fluorophenyl)urea, N-(1-ethyl-3-(4-fluoro-5-(3-(3-fluorophenyl)ureido)-2-methylphenyl)-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)acetamide, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-((4-methylpiperazin-1-yl)methyl)phenyl)urea, N-(1-ethyl-3-(4-fluoro-2-methyl-5-(3-phenylureido)phenyl)-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)acetamide, N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-3-hydroxyazetidine-1-carboxamide, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(3-((4-methylpiperazin-1-yl)methyl)phenyl)urea, 1-(4-bromo-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-((4-methylpiperazin-1-yl)methyl)phenyl)urea, (R)—N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-3-(dimethylamino)pyrrolidine-1-carboxamide, (S)—N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)pyrrolidine-2-carboxamide, N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-isopropyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)acetamide, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(4-fluoro-3-((4-methylpiperazin-1-yl)methyl)phenyl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-fluoro-5-((4-methylpiperazin-1-yl)methyl)phenyl)urea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(4-fluoro-3-((4-methylpiperazin-1-yl)methyl)phenyl)urea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)-3-(4-fluoro-3-((4-methylpiperazin-1-yl)methyl)phenyl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-cyanophenyl)urea, 1-(4-chloro-5-(1-ethyl-7-((3-morpholinopropyl)amino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(5-(7-amino-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(4-fluoro-3-((4-methylpiperazin-1-yl)methyl)phenyl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-((dimethylamino)methyl)-4-fluorophenyl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(4-fluoro-3-(morpholinomethyl)phenyl)urea, (S)—N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-3-(dimethylamino)pyrrolidine-1-carboxamide, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(4-fluoro-3-(pyrrolidin-1-ylmethyl)phenyl)urea, 3-(3-(2-chloro-4-fluoro-5-(3-(3-fluorophenyl)ureido)phenyl)-1-isopropyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, N-(3-(2-chloro-4-fluoro-5-(3-(3-fluorophenyl)ureido)phenyl)-1-isopropyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)acetamide, N-(1-ethyl-3-(4-fluoro-5-(3-(4-fluoro-3-((4-methyl)piperazin-1-yl)methyl)phenyl)ureido)-2-methylphenyl)-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)formamide, 3-(1-ethyl-3-(4-fluoro-2-methyl-5-(3-phenylureido)phenyl)-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-3-(dimethylamino)azetidine-1-carboxamide, 3-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-isopropyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, 3-(3-(5-(3-(benzo[b]thiophen-3-yl)ureido)-4-fluoro-2-methylphenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, 3-(3-(2-bromo-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea,

3-(1-ethyl-3-(4-fluoro-5-(3-(3-fluorophenyl)ureido)-2-methylphenyl)-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, N-(3-(2-chloro-4-fluoro-5-(3-(4-fluoro-3-(morpholinomethyl)phenyl)ureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)formamide, 3-(3-(5-(3-(3,5-difluorophenyl)ureido)-4-fluoro-2-methylphenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, N-(3-(4-fluoro-2-methyl-5-(3-phenylureido)phenyl)-1-isopropyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)azetidine-1-carboxamide, N-(1-ethyl-3-(4-fluoro-2-methyl-5-(3-phenylureido)phenyl)-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)azetidine-1-carboxamide, 1-(5-(1-ethyl-7-((6-methylpyridin-3-yl)amino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-phenylurea, 3-(3-(2,4-difluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, 3-(dimethylamino)-N-(1-ethyl-3-(4-fluoro-2-methyl-5-(3-phenylureido)phenyl)-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)azetidine-1-carboxamide, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-iodophenyl)-3-phenylurea, and 1-(5-(1-ethyl-7-((1-methyl-1H-pyrazol-4-yl)amino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-phenylurea; or a pharmaceutically acceptable salt thereof.

In some embodiments, the present invention comprises a compound selected from the group consisting of 1-(4-chloro-3-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(3-cyanophenyl)urea, 1-(3-cyanophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)urea, 1-(benzo[b]thiophen-3-yl)-3-(2-fluoro-4-methyl-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)urea, 1-(benzo[b]thiophen-3-yl)-3-(2,4-difluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)urea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)-3-(3-fluorophenyl)urea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)-3-phenylurea, 1-(3-chlorophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)urea, 1-(3-cyanophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)urea, 1-(benzo[b]thiophen-3-yl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)urea, 1-(5-(7-amino-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-4-chloro-2-fluorophenyl)-3-(3-fluorophenyl)urea, 1-(5-(7-amino-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-4-chloro-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-2-fluoro-5-(1-isopropyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-phenylurea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-phenylurea, 1-[4-chloro-5-(1-ethyl-7-methylamino-2-oxo-1,2-dihydro-[1,6]naphthyridin-3-yl)-2-fluoro-phenyl]-3-(3-fluoro-phenyl)-urea, 1-[4-chloro-5-(1-ethyl-7-methylamino-2-oxo-1,2-dihydro-[1,6]naphthyridin-3-yl)-2-fluoro-phenyl]-3-(2-fluoro-phenyl)-urea, 1-(4-chloro-3-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea,

1-(4-chloro-5-(1-ethyl-7-(1-methylpiperidin-4-ylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-2-oxo-7-(THF-3-ylamino)-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(2-(methylsulfonyl)ethylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(1-methylpyrrolidin-3-ylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-bromo-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-fluorophenyl)urea, 1-(4-bromo-5-(1-ethyl-7-(2-methoxyethylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-bromo-5-(1-ethyl-7-(2-(methylsulfonyl)ethylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(5-(7-acetamido-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-4-bromo-2-fluorophenyl)-3-phenylurea, 1-(5-(7-acetamido-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-4-chloro-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3,5-difluorophenyl)urea, 1-(4-bromo-2-fluoro-5-(1-methyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-phenylurea, 1-(5-(7-amino-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-4-bromo-2-fluorophenyl)-3-phenylurea, 1-(5-(7-amino-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(3-fluorophenyl)urea, 1-(benzo[b]thiophen-3-yl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)urea, 1-(3,5-difluorophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)urea, 1-(2,5-difluorophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)urea, 1-(2,5-difluorophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2,4a,8a-tetrahydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)urea, 1-(3,5-difluorophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2,4a,8a-tetrahydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)urea, N-(3-(2-bromo-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-2-cyanoacetamide, N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-2-cyanoacetamide, 1-(5-(7-acetamido-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)-3-phenylurea, N-(3-(2-chloro-5-(3-(3,5-difluorophenyl)ureido)-4-fluorophenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)acetamide, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(2,5-difluorophenyl)urea, 1-(3-chloro-5-fluorophenyl)-3-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)urea, 3-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-chloro-5-fluorophenyl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-fluoro-5-methylphenyl)urea, methyl (3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)carbamate, N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-2-methoxyacetamide, 2-cyano-N-(3-(2,4-difluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)acetamide, 1-(4-cyano-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(4-chloro-2-fluoro-5-(1-isopropyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)phenyl)-3-(3-fluorophenyl)urea, N-(1-ethyl-3-(4-fluoro-5-(3-(3-fluorophenyl)ureido)-2-methylphenyl)-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)acetamide, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-((4-methylpiperazin-1-yl)methyl)phenyl)urea, N-(1-ethyl-3-(4-fluoro-2-methyl-5-(3-phenylureido)phenyl)-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)acetamide, N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-3-hydroxyazetidine-1-carboxamide, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(3-((4-methyl)piperazin-1-yl)methyl)phenyl)urea, 1-(4-bromo-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-((4-methyl)piperazin-1-yl)methyl)phenyl)urea, (R)—N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-3-(dimethylamino)pyrrolidine-1-carboxamide, (S)—N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)pyrrolidine-2-carboxamide, N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-isopropyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)acetamide, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(4-fluoro-3-((4-methyl)piperazin-1-yl)methyl)phenyl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-fluoro-5-((4-methylpiperazin-1-yl)methyl)phenyl)urea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(4-fluoro-3-((4-methyl)piperazin-1-yl)methyl)phenyl)urea, 1-(5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2,4-difluorophenyl)-3-(4-fluoro-3-((4-methyl)piperazin-1-yl)methyl)phenyl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-cyanophenyl)urea, 1-(4-chloro-5-(1-ethyl-7-((3-morpholinopropyl)amino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea, 1-(5-(7-amino-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(4-fluoro-3-((4-methylpiperazin-1-yl)methyl)phenyl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-((dimethylamino)methyl)-4-fluorophenyl)urea, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(4-fluoro-3-(morpholinomethyl)phenyl)urea, (S)—N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-3-(dimethylamino)pyrrolidine-1-carboxamide, 1-(4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(4-fluoro-3-(pyrrolidin-1-ylmethyl)phenyl)urea, 3-(3-(2-chloro-4-fluoro-5-(3-(3-fluorophenyl)ureido)phenyl)-1-isopropyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, N-(3-(2-chloro-4-fluoro-5-(3-(3-fluorophenyl)ureido)phenyl)-1-isopropyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)acetamide, N-(1-ethyl-3-(4-fluoro-5-(3-(4-fluoro-3-((4-methylpiperazin-1-yl)methyl)phenyl)ureido)-2-methylphenyl)-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)formamide, 3-(1-ethyl-3-(4-fluoro-2-methyl-5-(3-phenylureido)phenyl)-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, N-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-3-(dimethylamino)azetidine-1-carboxamide, 3-(3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-isopropyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, 3-(3-(5-(3-(benzo[b]thiophen-3-yl)ureido)-4-fluoro-2-methylphenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea, 3-(3-(2-bromo-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)-1,1-dimethylurea,

For convenience, certain terms employed in the specification, examples and claims are collected here. Unless defined otherwise, all technical and scientific terms used in this disclosure have the same meanings as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The initial definition provided for a group or term provided in this disclosure applies to that group or term throughout the present disclosure individually or as part of another group, unless otherwise indicated.

The compounds of this disclosure include any and all possible isomers, stereoisomers, enantiomers, diastereomers, tautomers, pharmaceutically acceptable salts, and solvates thereof, as well as crystalline polymorphic forms of the disclosed compounds and any and all possible isomers, stereoisomers, enantiomers, diastereomers, tautomers, pharmaceutically acceptable salts, and solvates thereof. Thus, the terms “compound,” “compounds,” “test compound,” or “test compounds” as used in this disclosure refer to the compounds of this disclosure and any and all possible isomers, stereoisomers, enantiomers, diastereomers, tautomers, pharmaceutically acceptable salts, solvates, and crystalline polymorphs thereof.

DEFINITIONS

The term “alkyl” as used herein refers to straight chain alkyl, wherein alkyl chain length is indicated by a range of numbers, In exemplary embodiments, “alkyl” refers to an alkyl chain as defined above containing 1, 2, 3, 4, 5, or 6 carbons (i.e., C1-C6 alkyl). Examples of an alkyl include, but are not limited to, methyl, ethyl, propyl, butyl, pentyl, and hexyl.

The term “branched alkyl” as used herein refers to an alkyl chain wherein a branching point in the chain exists, and the total number of carbons in the chain is indicated by a range of numbers. In exemplary embodiments, “branched alkyl” refers to an alkyl chain as defined above containing 3, 4, 5, 6, or 7 carbons (i.e., C3-C7 branched alkyl). Examples of branched alkyl include, but are not limited to, iso-propyl, iso-butyl, secondary-butyl, tertiary-butyl, 2-pentyl, 3-pentyl, 2-hexyl, and 3-hexyl.

The term “alkoxy” as used herein refers to —O-(alkyl), wherein “alkyl” is as defined above.

The term “branched alkoxy” as used herein refers to —O-(branched alkyl), wherein “branched alkyl” is as defined above.

The term “alkylene” as used herein refers to an alkyl moiety interposed between two other atoms. In exemplary embodiments, “alkylene” refers to an alkyl moiety as defined above containing 1, 2, or 3 carbons. Examples of an alkylene group include, but are not limited to —CH₂—, —CH₂CH₂—, and —CH₂CH₂CH₂—. In exemplary embodiments, alkylene groups are branched.

The term “alkynyl” as used herein refers to a carbon chain containing one carbon-carbon triple bond. In exemplary embodiments, “alkynyl” refers to a carbon chain as described above containing 2 or 3 carbons (i.e., C2-C3 alkynyl). Examples of an alkynyl group include, but are not limited to, ethyne and propyne.

The term “aryl” as used herein refers to a cyclic hydrocarbon, where the ring is characterized by delocalized π electrons (aromaticity) shared among the ring members, and wherein the number of ring atoms is indicated by a range of numbers. In exemplary embodiments, “aryl” refers to a cyclic hydrocarbon as described above containing 6, 7, 8, 9, or 10 ring atoms (i.e., C6-C10 aryl). Examples of an aryl group include, but are not limited to, benzene, naphthalene, tetralin, indene, and indane.

The term “cycloalkyl” as used herein refers to a monocyclic saturated carbon ring, wherein the number of ring atoms is indicated by a range of numbers. In exemplary embodiments, “cycloalkyl” refers to a carbon ring as defined above containing 3, 4, 5, 6, 7, or 8 ring atoms (i.e., C3-C8 cycloalkyl). Examples of a cycloalkyl group include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.

The term “halogen” or “halo” as used herein refers to fluorine, chlorine, bromine, and iodine.

The term “heterocycle” or “heterocyclyl” as used herein refers to a cyclic hydrocarbon, wherein at least one of the ring atoms is an O, N, or S, wherein the number of ring atoms is indicated by a range of numbers. Heterocyclyl moieties as defined herein have C or N bonding hands. For example, in some embodiments, a ring N atom from the heterocyclyl is the bonding atom of the heterocylic moiety. In exemplary embodiments, “heterocyclyl” refers to a cyclic hydrocarbon as described above containing 4, 5, or 6 ring atoms (i.e., C4-C6 heterocyclyl). Examples of a heterocycle group include, but are not limited to, aziridine, oxirane, thiirane, azetidine, oxetane, thietane, pyrrolidine, tetrahydrofuran, pyran, thiopyran, thiomorpholine, thiomorpholine S-oxide, thiomorpholine S-dioxide, oxazoline, tetrahydrothiophene, piperidine, tetrahydropyran, thiane, imidazolidine, oxazolidine, thiazolidine, dioxolane, dithiolane, piperazine, oxazine, dithiane, and dioxane.

The term “heteroaryl” as used herein refers to a cyclic hydrocarbon, where at least one of the ring atoms is an O, N, or S, the ring is characterized by delocalized π electrons (aromaticity) shared among the ring members, and wherein the number of ring atoms is indicated by a range of numbers. Heteroaryl moieties as defined herein have C or N bonding hands. For example, in some embodiments, a ring N atom from the heteroaryl is the bonding atom of the heteroaryl moiety. In exemplary embodiments, “heteroaryl” refers to a cyclic hydrocarbon as described above containing 5 or 6 ring atoms (i.e., C5-C6 heteroaryl). Examples of a heteroaryl group include, but are not limited to, pyrrole, furan, thiene, oxazole, thiazole, isoxazole, isothiazole, imidazole, pyrazole, oxadiazole, thiadiazole, triazole, tetrazole, pyridine, pyrimidine, pyrazine, pyridazine, and triazine.

The term “substituted” in connection with a moiety as used herein refers to a further substituent which is attached to the moiety at any acceptable location on the moiety. Unless otherwise indicated, moieties can bond through a carbon, nitrogen, oxygen, sulfur, or any other acceptable atom.

The term “salts” as used herein embraces pharmaceutically acceptable salts commonly used to form alkali metal salts of free acids and to form addition salts of free bases. The nature of the salt is not critical, provided that it is pharmaceutically acceptable. Suitable pharmaceutically acceptable acid addition salts may be prepared from an inorganic acid or from an organic acid. Exemplary pharmaceutical salts are disclosed in Stahl, P. H., Wermuth, C. G., Eds. Handbook of Pharmaceutical Salts: Properties, Selection and Use; Verlag Helvetica Chimica Acta/Wiley-VCH: Zurich, 2002, the contents of which are hereby incorporated by reference in their entirety. Specific non-limiting examples of inorganic acids are hydrochloric, hydrobromic, hydroiodic, nitric, carbonic, sulfuric and phosphoric acid. Appropriate organic acids include, without limitation, aliphatic, cycloaliphatic, aromatic, arylaliphatic, and heterocyclyl containing carboxylic acids and sulfonic acids, for example formic, acetic, propionic, succinic, glycolic, gluconic, lactic, malic, tartaric, citric, ascorbic, glucuronic, maleic, fumaric, pyruvic, aspartic, glutamic, benzoic, anthranilic, mesylic, stearic, salicylic, p-hydroxybenzoic, phenylacetic, mandelic, embonic (pamoic), methanesulfonic, ethanesulfonic, benzenesulfonic, pantothenic, toluenesulfonic, 2-hydroxyethanesulfonic, sulfanilic, cyclohexylaminosulfonic, algenic, 3-hydroxybutyric, galactaric or galacturonic acid. Suitable pharmaceutically acceptable salts of free acid-containing compounds disclosed herein include, without limitation, metallic salts and organic salts. Exemplary metallic salts include, but are not limited to, appropriate alkali metal (group Ia) salts, alkaline earth metal (group IIa) salts, and other physiological acceptable metals. Such salts can be made from aluminum, calcium, lithium, magnesium, potassium, sodium and zinc. Exemplary organic salts can be made from primary amines, secondary amines, tertiary amines and quaternary ammonium salts, for example, tromethamine, diethylamine, tetra-N-methylammonium, N,N′-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine (N-methylglucamine) and procaine.

The terms “administer,” “administering, or “administration” as used herein refer to either directly administering a compound or pharmaceutically acceptable salt of the compound or a composition to a subject.

The term “carrier” as used herein encompasses carriers, excipients, and diluents, meaning a material, composition or vehicle, such as a liquid or solid filler, diluent, excipient, solvent or encapsulating material involved in carrying or transporting a pharmaceutical agent from one organ, or portion of the body, to another organ or portion of the body.

The term “disorder” is used in this disclosure to mean, and is used interchangeably with, the terms disease, condition, or illness, unless otherwise indicated.

The terms “effective amount” and “therapeutically effective amount” are used interchangeably in this disclosure and refer to an amount of a compound that, when administered to a subject, is capable of reducing a symptom of a disorder in a subject. The actual amount which comprises the “effective amount” or “therapeutically effective amount” will vary depending on a number of conditions including, but not limited to, the particular disorder being treated, the severity of the disorder, the size and health of the patient, and the route of administration. A skilled medical practitioner can readily determine the appropriate amount using methods known in the medical arts.

The terms “isolated” and “purified” as used herein refer to a component separated from other components of a reaction mixture or a natural source. In certain embodiments, the isolate contains at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% of the compound or pharmaceutically acceptable salt of the compound by weight of the isolate.

The phrase “pharmaceutically acceptable” as used herein refers to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.

As used in this disclosure, the terms “patient” or “subject” include, without limitation, a human or an animal. Exemplary animals include, but are not limited to, mammals such as mouse, rat, guinea pig, dog, cat, horse, cow, pig, monkey, chimpanzee, baboon, or rhesus monkey.

“Therapeutically effective amount” or “effective amount” means the dosage of the compound, or pharmaceutically acceptable salt thereof, or pharmaceutical composition containing an exemplified compound of Formula I, or pharmaceutically acceptable salt thereof, necessary to inhibit c-KIT signaling in a cancer patient, and either destroy the target cancer cells or slow or arrest the progression of the cancer in a patient. The exact dosage required to treat a patient and the length of treatment time will be determined by a physician in view of the stage and severity of the disease as well as the specific needs and response of the individual patient and the particular compound administered. Although expressed as dosage on a per day basis, the dosing regimen may be adjusted to provide a more optimal therapeutic benefit to a patient. In addition to daily dosing, twice-a-day (BID) or thrice-a-day (TID) dosing may be appropriate. BID dosing is currently preferred.

The terms “treatment,” “treat,” and “treating,” are meant to include the full spectrum of intervention for the cancer from which the patient is suffering, such as administration of the active compound to alleviate, slow or reverse one or more of the symptoms and to delay progression of the cancer even if the cancer is not actually eliminated. Treating can be curing, improving, or at least partially ameliorating the disorder. The patient to be treated is a mammal, in particular a human being.

The term “hydrate” as used herein refers to a compound disclosed herein which is associated with water in the molecular form, i.e., in which the H—OH bond is not split, and may be represented, for example, by the formula R.H₂O, where R is a compound disclosed herein. A given compound may form more than one hydrate including, for example, monohydrates (R.H₂O), dihydrates (R.2H₂O), trihydrates (R.3H₂O), and the like.

The term “solvate” as used herein refers to a compound disclosed herein which is associated with solvent in the molecular form, i.e., in which the solvent is coordinatively bound, and may be represented, for example, by the formula R.(solvent), where R is a compound disclosed herein. A given compound may form more than one solvate including, for example, monosolvates (R.(solvent)) or polysolvates (R.n(solvent)) wherein n is an integer greater than 1) including, for example, disolvates (R.2(solvent)), trisolvates (R.3(solvent)), and the like, or hemisolvates, such as, for example, R.n/2(solvent), R.n/3(solvent), R.n/4(solvent) and the like, wherein n is an integer. Solvents herein include mixed solvents, for example, methanol/water, and as such, the solvates may incorporate one or more solvents within the solvate.

The term “acid hydrate” as used herein refers to a complex that may be formed through association of a compound having one or more base moieties with at least one compound having one or more acid moieties or through association of a compound having one or more acid moieties with at least one compound having one or more base moieties, said complex being further associated with water molecules so as to form a hydrate, wherein said hydrate is as previously defined and R represents the complex herein described above.

Structural, chemical and stereochemical definitions are broadly taken from IUPAC recommendations, and more specifically from Glossary of Terms used in Physical Organic Chemistry (IUPAC Recommendations 1994) as summarized by Müller, P. Pure Appl. Chem. 1994, 66, pp. 1077-1184 and Basic Terminology of Stereochemistry (IUPAC Recommendations 1996) as summarized by Moss, G. P. Pure Appl. Chem. 1996, 68, pp. 2193-2222.

Atropisomers are defined as a subclass of conformers which can be isolated as separate chemical species and which arise from restricted rotation about a single bond.

Regioisomers or structural isomers are defined as isomers involving the same atoms in different arrangements.

Enantiomers are defined as one of a pair of molecular entities which are mirror images of each other and non-superimposable.

Diastereomers or diastereoisomers are defined as stereoisomers other than enantiomers. Diastereomers or diastereoisomers are stereoisomers not related as mirror images. Diastereoisomers are characterized by differences in physical properties, and by some differences in chemical behavior towards achiral as well as chiral reagents.

The term “tautomer” as used herein refers to compounds produced by the phenomenon wherein a proton of one atom of a molecule shifts to another atom. See March, Advanced Organic Chemistry: Reactions, Mechanisms and Structures, 4th Ed., John Wiley & Sons, pp. 69-74 (1992). Tautomerism is defined as isomerism of the general form
G-X—Y═Z

X═Y—Z-G
where the isomers (called tautomers) are readily interconvertible; the atoms connecting the groups X, Y and Z are typically any of C, H, O, or S, and G is a group which becomes an electrofuge or nucleofuge during isomerization. The most common case, when the electrofuge is H⁺, is also known as “prototropy.” Tautomers are defined as isomers that arise from tautomerism, independent of whether the isomers are isolable.

The exemplified compounds of the present invention are preferably formulated as a pharmaceutical composition using a pharmaceutically acceptable carrier and administered by a variety of routes. Preferably, such compositions are for oral administration. Such pharmaceutical compositions and processes for preparing them are well known in the art. See, e.g., REMINGTON: THE SCIENCE AND PRACTICE OF PHARMACY (A. Gennaro, et al., eds., 19^thed., Mack Publishing Co., 1995). In a particular embodiment, the pharmaceutical composition comprises 1-(3,3-dimethylbutyl)-3-{2-fluoro-4-methyl-5-[7-methyl-2-(methylamino)pyrido[2,3-d]pyrimidin-6-yl]phenyl}urea, or a pharmaceutically acceptable salt thereof, together with a pharmaceutically acceptable carrier and optionally other therapeutic ingredients particularly for treatment of cancer generally or a specific cancer type.

The exemplified compounds of the present invention are capable of reaction with a number of inorganic and organic acids to form pharmaceutically acceptable acid addition salts. Such pharmaceutically acceptable salts and common methodology for preparing them are well known in the art. See, e.g., P. Stahl, et al., HANDBOOK OF PHARMACEUTICAL SALTS: PROPERTIES, SELECTION AND USE, (VCHA/Wiley-VCH, 2002); S. M. Berge, et al., “Pharmaceutical Salts,” Journal of Pharmaceutical Sciences, Vol. 66, No. 1, January 1977.

The compounds of Formula Ia, or a pharmaceutically acceptable salt thereof, may be prepared by a variety of procedures known in the art, as well as those described below. The specific synthetic steps may be combined in different ways to prepare the Formula Ia compounds, or a pharmaceutically acceptable salt thereof.

The compounds employed as initial starting materials in the synthesis of the compounds of Formula Ia are well known and, to the extent not commercially available, are readily synthesized using specific references provided, by standard procedures commonly employed by those of ordinary skill in the art, or are found in general reference texts.

Examples of known procedures and methods include those described in general reference texts such as Comprehensive Organic Transformations, VCH Publishers Inc, 1989; Compendium of Organic Synthetic Methods, Volumes 1-10, 1974-2002, Wiley Interscience; Advanced Organic Chemistry, Reactions Mechanisms, and Structure, 5^thEdition, Michael B. Smith and Jerry March, Wiley Interscience, 2001; Advanced Organic Chemistry, 4^thEdition, Part B, Reactions and Synthesis, Francis A. Carey and Richard J. Sundberg, Kluwer Academic/Plenum Publishers, 2000, etc., and references cited therein.

ChemDraw version 10 or 12 (CambridgeSoft Corporation, Cambridge, Mass.) was used to name the structures of intermediates and exemplified compounds.

The following abbreviations are used in this disclosure and have the following definitions: “ADP” is adenosine diphosphate, “AIBN” is azobisisobutyronitrile, “ATP” is adenosine triphosphate, “BippyPhos” is 5-(di-tert-butylphosphino)-1′,3′,5′-triphenyl-1′H-[1,4′]bipyrazole, “BrettPhos Palladacycle” is chloro[2-(dicyclohexylphosphino)-3,6-dimethoxy-2′-4′-6′-tri-1-propyl-1,1′-biphenyl][2-(2-aminoethyl)phenyl]palladium(II), “conc.” is concentrated, “DBU” is 1,8-diazabicyclo[5.4.0]undec-7-ene, “DCM” is dichloromethane, “DIEA” is N,N-diisopropylethylamine, “DMA” is N,N-dimethylacetamide, “DMAP” is 4-(dimethylamino)pyridine, “DMF” is N,N-dimethylformamide, “DMSO” is dimethylsulfoxide, “DPPA” is diphenylphosphryl azide, “DTT” is dithiothreitol, “ESI” is electrospray ionization, “Et₂O” is diethylether, “EtOAc” is ethyl acetate, “EtOH” is ethanol, “GST” is glutathione S-transferase, “h” is hour or hours, “Hex” is hexane, “IC₅₀” is half maximal inhibitory concentration, “IPA” refers to isopropyl alcohol, “KF/Al₂O₃” is potassium fluoride on alumina, “mCPBA” is 3-chloroperbenzoic acid, “MeCN” is acetonitrile, “MeOH” is methanol, “MHz” is megahertz, “min” is minute or minutes, “MS” is mass spectrometry, “MTBE” is methyl tert-butyl ether, “NADH” is nicotinamide adenine dinucleotide, “NBS” is N-bromosuccinimide, “NMP” is 1-methyl-2-pyrrolidinone, “NMR” is nuclear magnetic resonance, “PBS” is phosphate buffered saline, “Pd/C” is palladium on carbon, “Pd(OAc)₂” is palladium(II) acetate, “Pd₂(dba)₃” is tris(dibenzylideneacetone)dipalladium(0), “pet ether” is petroleum ether, “prep-HPLC” is preparative high performance liquid chromatography, “prep-TLC” is preparative thin layer chromatography, “RT” is room temperature which is also known as “ambient temp,” which will be understood to consist of a range of normal laboratory temperatures ranging from 15-25° C., “satd.” is saturated, “t-butyl-X-Phos” is 2-di-tert-butylphosphino-2′,4′,6′-triisopropylbiphenyl, “TEA” is triethylamine, “TFA” is trifluoroacetic acid, “THF” is tetrahydrofuran, “Tris” is tris(hydroxymethyl)aminomethane, “Xantphos” is 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, and “X-Phos” is 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl.

General Chemistry

The compounds of Formula Ia (1) are prepared by the general synthetic methods illustrated in the schemes below and the accompanying examples. Suitable reaction conditions for the steps of these schemes are well known in the art and appropriate substitutions of solvents and co-reagents are within the skill of the art. Those skilled in the art will understand that synthetic intermediates may be isolated and/or purified by well known techniques as needed or desired, and that it will be possible to use various intermediates directly in subsequent synthetic steps with little or no purification. Furthermore, those skilled in the art will appreciate that in some instances, the order in which moieties are introduced is not critical. The particular order of steps required to produce the compounds of Formula I is dependent upon the particular compound being synthesized, the starting compound, and the relative liability of the substituted moieties, as is well appreciated by the ordinary skilled chemist. All substituents, unless otherwise indicated, are as defined above.

The compounds of Formula Ia (1) frequently contain —NH moieties in the Z1 position. It will be understood by those skilled in the art that in some instances it may be advantageous to use an amine protecting group during synthesis to temporarily mask one or more —NH moieties. Said protecting group can be removed from any subsequent intermediate leading to the synthesis of compound I, using standard conditions that effect removal of said protecting group, said conditions of which will be familiar to those skilled in the art. When not specified in a scheme, it will be understood by those skilled in the art that the Z1 moiety represented in the schemes below may optionally contain a standard NH-protecting group that can be removed at any opportune time in the synthetic sequence. For example, intermediates wherein Z1 is aminomethyl, may be obtained directly by the introduction of methylamine into a synthetic scheme, or alternately by introduction of a “protected” form of methylamine, for example 1-(4-methoxyphenyl)-N-methylmethanamine to provide intermediates wherein Z1 is 1-(4-methoxyphenyl)-N-methylmethanamino. Even if not specifically drawn, the schemes below implicitly include de-protection of any protected Z1 moiety immediately after introduction, or optionally at any subsequent step of the synthesis.

Scheme 1 illustrates general preparations of compounds of formula 1 from 7-chloro-naphthyridinone 2. Conversion of chloride 2 to Z1-substituted intermediate 3 can be accomplished by numerous methods familiar to those skilled in art, the choice of which is dictated by the specific nature of Z1. Further conversion of intermediate 3 to ureas of formula 1 is accomplished by one of three methods. In one embodiment, reaction of 3 with isocyanates of formula 4 provides ureas of formula 1. Many isocyanates (4) are commercially available and those that are not can be readily prepared from the corresponding amines (9) by reaction of said amines with phosgene or an equivalent such as triphosgene or carbonyl diimidazole. Conditions to effect the transformation of 3 to 1 include treating 3 with 4 in an aprotic solvent such as DCM, THF or EtOAc, optionally in the presence of a base, for example pyridine, and optionally while heating said mixtures. In a second embodiment, reaction of 3 with carbamates of formula 5 also affords ureas of formula 1. Conditions to effect the transformation of 3 to 1 include treating 3 with 5 in an aprotic solvent such as 1,4-dioxane, THF or DMSO, in the presence of a base, for example N-methylpyrrolidine, diisopropylethylamine, or triethylamine, and heating the resulting mixture. Suitable carbamates (5) include isopropenyl, 2,2,2,-trichloroethyl and phenyl (or substituted phenyl) carbamates. These carbamates 5 can be readily prepared by reaction with amines 9 with the appropriate chloroformate as familiar to those skilled in the art. In a third embodiment, carboxylic acids of formula 5 can be subjected to a Curtius rearrangement in the presence of amine 3 to provide ureas of formula 1. Conditions to effect said transformation include combining amine 3, carboxylic acid 5 and diphenylphosphoryl azide (DPPA), and a base, for example triethylamine, and heating said mixture in an aprotic solvent, such as 1,4-dioxane, in a temperature range of 50-120° C. to effect the rearrangement.

In addition to these methods, compound 3 can also be converted to 1 via two-step process by first converting 3 to carbamate 8, followed by reaction of carbamate 8 with amine 9. As before, suitable carbamates (8) include isopropenyl, 2,2,2,-trichloroethyl and phenyl (or substituted phenyl) carbamates. These carbamates 8 can be readily prepared by reaction of amine 3 with the appropriate chloroformate 11 (for example, R=2-propenyl, 2,2,2-trichloroethyl, or phenyl). In one embodiment, reaction of amine 3 with isopropenyl chloroformate and sodium bicarbonate in a mixed solvent of EtOAc and water provides carbamate 8 (R=2-propenyl). Further treatment of carbamate 8 with amine 9 in an aprotic solvent such as 1,4-dioxane, THF or DMSO, in the presence of a base, for example N-methylpyrrolidine, diisopropylethylamine, or triethylamine, and heating the resulting mixture provides compounds of formula 1.

By analogy to the conversion of 3 to 1 or 3 to 8, 7-chloro-naphthyridinone 2 can also be converted to urea 7 or carbamate 10, respectively. Further conversion of urea 7 to urea 1 is then accomplished by reaction of 7 with a generic Z1 amine, amide, urea or carbamic acid in the presence of a Palladium catalyst (Buchwald-type coupling), as further illustrated below.

Scheme 2 illustrates the preparation of compounds of formula 15, compounds of formula 1 wherein Z1 is —NHR4. In one embodiment, 7-chloro-naphthyridinone 2 is reacted with amine 12a (P═H), or 12b (P is a standard amine protecting group such as 4-methoxybenzyl or tert-butoxycarbonyl) to provide 13 or 14 respectively. Conditions for the conversion of 2 to 13 or 14 include heating an amine of formula 12a or 12b with chloride 2, optionally in the presence of an additional base, for example DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), and optionally in the presence of microwave irradiation. When “P” represents a protecting group, said group of 14 may be removed by suitable conditions familiar to the skilled chemist, for example by treatment with TFA when “P” is 4-methoxybenzyl, to provide 13. Using one of the three methods described for scheme 1, compound 13 or 14 can be converted to ureas 15 or 16, respectively. In the event that “P” represents a protecting group, said group of 16 may be removed by suitable conditions familiar to the skilled chemist to provide 15. Alternately, as described in scheme 1, amines 13 or 14 can be converted to carbamates 17 or 18. Further reaction of these carbamates with amine 9 provides ureas 15 or 16. Finally, ureas 15 or 16 can also be prepared from chloride 7 (scheme 1) by reaction with amine 12a or 12b in the presence of a suitable palladium catalyst, for example the catalyst prepared from Pd(OAc)₂or Pd₂(dba)₃[tris(dibenzylideneacetone)dipalladium] and a ligand such as Xantphos [4,5-bis(diphenylphosphino)-9,9-dimethylxanthene] or BippyPhos [5-(di-tert-butylphosphino)-1′,3′,5′-triphenyl-1′H-[1,4′]bipyrazole] in the presence of a base, for example K₂CO₃.

Scheme 3 illustrates the preparation of 21, a compound of formula 1 wherein Z1 is —N(R4)COR8. Using methods described in scheme 2, treatment of chlorides 2 or 7 with generic carbonylamine 19 in the presence of a suitable palladium catalyst provides amides, ureas, or carbamates (according to the R8 moiety) of formula 20 or 21 respectively. Further conversion of 20 to 21 is accomplished, as described above, by treatment of 20 with 4, 5, or 6. Alternately, 20 can first be converted to carbamate 22. As described above, further treatment of 22 with amine 9 provides urea 21.

Scheme 4 illustrates alternate preparations of 21, 27 and 28 starting from intermediate 15 (scheme 2). Treatment of 15 with a carbonylation reagent 23 according to conditions familiar to the skilled artisan affords urea 21. The X-moiety of 23 represents a generalized leaving group. Examples of X—(CO)R8 23 include acid chlorides (X═Cl, R8=alkyl) or anhydrides (X═O(CO)R8), and chloroformates (X═Cl, R8=alkoxy). Those skilled in the art will recognize that in the instance in which R8 is —NHR4, isocyanates of formula R4-NCO can be substituted for 23. Additionally, when R8 is an amine, the resulting ureas 27 and 28 can be prepared by reaction of a suitable carbamate 24 with amine 25 or heterocyclic amine 26, respectively. Suitable carbamates include alkyl, isopropenyl, 2,2,2,-trichloroethyl and phenyl (or substituted phenyl) carbamates. These carbamates 24 can be readily prepared by reaction of amine 15 with the appropriate chloroformate 11 (for example, R=2-propenyl, 2,2,2-trichloroethyl, or phenyl).

Scheme 5 illustrates the general preparation of 7-chloro-naphthyridinones 2. Treatment of ethyl 4,6-dichloronicotinate (29, see: Example C3) with R1-NH₂30 provides the 4-aminopyridine 31. Conditions for this transformation include polar solvents such as DMF, THF, acetonitrile, dioxane, water or mixtures thereof in the presence of optionally added bases such as triethylamine at temperatures between 0° C. and 100° C. Reduction of 31, for example by treatment with lithium aluminum hydride in THF at temperatures ranging from 0° C. to room temp, provides alcohol 32. Oxidation of 32 with manganese dioxide provides aldehyde 33. Condensation of 33 with phenylacetate 34 provides general intermediate 2. Conditions for this transformation include combining 33 and 34 in DMF or DMAc in the presence of potassium carbonate or cesium carbonate with optional heating (30-150° C.) for a period of time ranging from 1 h to 4 days. Alternate conditions include combining 33, 34 and alumina-supported potassium fluoride in DMAc with stirring and/or optional sonication and/or optional heating (30-150° C.) for a period of 10 min to 48 h.

Scheme 6 illustrates a general preparation of ester 34. Nitration of R2-substituted phenylacetic acid 35, for example by treatment with nitric acid and sulfuric acid provides 36. Acid 36 in turn is converted to ethyl ester 37, for example by heating in EtOH in the presence of an acid, such as sulfuric acid. Finally, reduction of the nitro group provides 34. Suitable conditions for this transformation include both hydrogenation over a palladium or nickel catalyst, or reduction with iron or zinc powder in the presence of a proton source, for example ethanolic HCl, acetic acid, or ammonium formate. Those skilled in the art will recognize the existence of numerous alternative preparations of general ethyl phenylacetate 34. One additional method is illustrated by the conversion of benzyl alcohol 38 to mesylate 39, homologation of mesylate 39 with cyanide to benzonitrile 40, and conversion of nitrile 40 to ethyl ester 34 by treatment with EtOH and HCl. Alcohol 38 can be obtained from the reduction of a suitably substituted benzoic acid or aldehyde, a sample preparation of which is disclosed below (Example A45).

EXAMPLES

The disclosure is further illustrated by the following examples, which are not to be construed as limiting this disclosure in scope or spirit to the specific procedures herein described. It is to be understood that the examples are provided to illustrate certain embodiments and that no limitation to the scope of the disclosure is intended thereby. It is to be further understood that resort may be had to various other embodiments, modifications, and equivalents thereof which may suggest themselves to those skilled in the art without departing from the spirit of the present disclosure and/or scope of the appended claims.

General Method A:

To a stirring solution of carboxylic acid (0.50 mmol, 1.00 eq) and DPPA (0.75 mmol, 1.50 eq) in 1,4-dioxane (5.0 mL) at RT was added TEA (1.5 mmol, 3.00 eq). After stirring for 30 min at RT, the appropriate amine (0.76 mmol, 1.50 eq) was added and the mixture was heated at 100° C. After 2 h, the completed reaction was cooled to RT, diluted with brine and extracted with EtOAc (2×). The combined organics were washed with 3M HCl (1×), satd. NaHCO₃(2×), and brine (1×), dried (MgSO₄), concentrated in vacuo to give the crude product which was purified by flash column chromatography to afford the target urea.

General Method B:

To a stirring suspension of isocyanate (0.51 mmol, 1.00 eq) and pyridine (0.0418 mL, 0.51 mmol, 1.00 eq) in DCM (5 mL) at RT was added the appropriate amine (0.51 mmol, 1.00 eq). A thick suspension gradually formed. After 3.5 h, the solids were collected by filtration, rinsed well with DCM and dried on the filter to afford the desired urea.

Example A1

Example A6 (1.61 g, 4.85 mmol), 4-methoxy-N-methylbenzylamine (1.10 g, 7.28 mmol) and DBU (1.09 mL, 7.28 mmol) were combined in NMP (20 mL) and heated at 180° C. under Ar overnight. The mixture was cooled to RT, poured into H₂O (200 mL) and the resulting solids were collected by filtration and rinsed well with H₂O. The solids were dried on the filter to dampness, dissolved in EtOAc, dried (MgSO₄), and evaporated to afford 3-(5-amino-4-fluoro-2-methylphenyl)-1-ethyl-7-((4-methoxybenzyl)(methyl)amino)-1,6-naphthyridin-2(1H)-one (2.06 g) as a brittle brown foam contaminated slightly with EtOAc and NMP. It was used as is in the next reaction.

Example A2

Using a procedure analogous to Example A8, Example A1 (2.06 g, 4.61 mmol) was converted to 3-(5-amino-4-fluoro-2-methylphenyl)-1-ethyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (1.16 g, 73% yield for 2 steps). ¹H NMR (400 MHz, DMSO-d₆): δ 8.36 (s, 1H), 7.58 (s, 1H), 6.94-6.92 (m, 1H), 6.83 (d, J=12.0 Hz, 1H), 6.57 (d, J=9.6 Hz, 1H), 4.87 (br s, 2H), 4.12 (q, J=6.8 Hz, 2H), 2.84 (d, J=4.8 Hz, 3H), 1.94 (s, 3H), 1.19 (t, J=7.2 Hz, 3H); MS (ESI) m/z: 327.2[M+H]⁺.

Example A3

A suspension mixture of Example B1 (3.5 g, 0.019 mol), Example C2 (4.4 g, 0.019 mol) and KF/Al₂O₃(10 g) in DMA was stirred at RT for 10 min, poured into water, and extracted with EtOAc (3×). The combined organic phases were washed with brine, dried (Na₂SO₄), concentrated in vacuo and purified by silica gel chromatography to give 3-(5-amino-2-chloro-4-fluorophenyl)-7-chloro-1-ethyl-1,6-naphthyridin-2(1H)-one (4 g, 60% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.75 (s, 1H), 8.01 (s, 1H), 7.72 (s, 1H), 7.24 (d, J=10.8 Hz, 1H), 6.76 (d, J=9.2 Hz, 1H), 5.40 (s, 2H), 4.26-4.24 (m, 2H), 1.18 (t, J=6.8 Hz, 3H); MS (ESI) m/z: 352.1 [M+H]⁺.

Example A4

A mixture of Example A3 (3 g, 8.5 mmol) and 1-(4-methoxyphenyl)-N-methylmethanamine (20 mL) was charged in a sealed vessel, and then the mixture was heated at 200° C. overnight. Volatiles were removed and the residue was purified by column chromatography to give 7-((4-methoxybenzyl)(methyl)amino)-3-(5-amino-2-chloro-4-fluorophenyl)-1-ethyl-1,6-naphthyridin-2(1H)-one (3 g, 73% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.47 (s, 1H), 7.70 (s, 1H), 7.18-7.17 (m, 3H), 6.86 (d, J=8.4 Hz, 2H), 6.73 (d, J=9.6 Hz, 1H), 6.30 (s, 1H), 5.31 (s, 2H), 4.84 (s, 2H), 4.17 (q, J=7.1 Hz, 2H), 3.70 (s, 3H), 3.12 (s, 3H), 1.11 (t, J=7.0 Hz, 3H); MS (ESI) m/z: 467.2 [M+H]⁺.

Example A5

To a solution of Example A4 (3 g, 6.2 mmol) in DCM (100 mL) was added TFA (20 mL) at RT, and the resulting mixture was stirred at RT for 6 h. The mixture was extracted with water (2×) and the combined aqueous layers were neutralized with NH₃H₂O. The resulting precipitate was collected by filtration and dried to give 3-(5-amino-2-chloro-4-fluorophenyl)-1-ethyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (1 g, 44% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.46 (s, 1H), 7.75 (s, 1H), 7.1 (d, J=11.2 Hz, 1H), 7.0 (m, 1H), 6.73 (d, J=9.6 Hz, 1H), 6.43 (s, 1H), 4.95 (br s, 2H), 4.14 (m, 2H), 2.92 (s, 3H), 1.14 (t, J=6.8 Hz, 3H); MS (ESI) m/z: 347.2 [M+H]⁺.

Example A6

Example C1 (1.32 g, 6.25 mmol, 1.00 eq), Example B1 (1.15 g, 6.25 mmol, 1.00 eq) and KF/Al₂O₃(40.00 wt %, 9.08 g, 62.5 mmol, 10.00 eq) were combined in DMA (35 mL) and sonicated for 2 h. The solids were removed via filtration through diatomaceous earth and washed with EtOAc. The combined filtrates were washed with H₂O (3×) and the combined aqueous layers were back-extracted with EtOAc (1×). The combined organics were washed with brine (2×), dried (MgSO₄), evaporated and purified by silica gel chromatography (EtOAc/Hex) to afford 3-(5-amino-4-fluoro-2-methylphenyl)-7-chloro-1-ethyl-1,6-naphthyridin-2(1H)-one (1.61 g, 78% yield) as a brittle foam. MS (ESI) m/z: 332.0 [M+H]⁺.

Example A7

A solution of Example A18 (22 g, 65.7 mmol), (4-methoxy-benzyl)-methyl-amine (14.9 g, 98.5 mmol) and DBU (15 g, 98.5 mmol) in NMP (120 mL) was heated at 160° C. for 5 h. The mixture was poured into 200 mL of water while stirring and the resulting solids were collected by filtration, washed with water, dried and then washed with Et₂O to give 3-(5-amino-2,4-difluoro-phenyl)-1-ethyl-7-[(4-methoxy-benzyl)-methyl-amino]-1H-[1,6]naphthyridin-2-one (25 g, yield 85% yield). ¹H NMR (300 MHz, DMSO-d₆): δ 8.51 (s, 1H), 7.80 (s, 1H), 7.19-7.17 (d, J=8.7 Hz, 2H), 7.06 (t, J=10.2 Hz, 1H), 6.90-6.81 (m, 3H), 6.32 (s, 1H), 5.02 (s, 2H), 4.86 (s, 2H), 4.19 (q, J=6.9 Hz, 2H), 3.72 (s, 3H), 3.14 (s, 3H), 1.14 (t, J=6.9 Hz, 3H); MS (ESI): m/z 451.1 [M+H]⁺.

Example A8

TFA (3.64 g, 32.0 mmol) was added to Example A7 (0.48 g, 1.06 mmol) and the mixture was stirred for 90 min at RT. Water (50 mL) was added and the reaction mixture was carefully treated with solid Na₂CO₃until it was weakly basic. The product was extracted with EtOAc (3×), the combined organics were washed with water (1×), then brine and dried (Na₂SO₄) to afford crude product which was stirred with DCM (2 mL) for 2 h. The resultant suspension was filtered, washed with DCM and dried to afford 3-(5-amino-2,4-difluorophenyl)-1-ethyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one as an off-white solid. (0.28 g, 60% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.39 (s, 1H), 7.73 (s, 1H), 7.06-7.01 (m, 2H), 6.79 (dd, J=10.0, 7.6 Hz, 1H), 6.21 (s, 1H), 4.99 (s, 2H), 4.12 (q, J=7.2 Hz, 2H), 2.84 (d, J=5.2 Hz, 3H), 1.19 (t, J=7.2 Hz, 3H); MS (ESI) m/z: 331.0 [M+H]⁺.

Example A9

A solution of Example A3 (1.90 g, 5.39 mmol), 4-methoxybenzylamine (1.110 g, 8.09 mmol) and DBU (1.232 g, 8.09 mmol) in NMP (15 mL) was heated at 150° C. overnight. After cooling to RT, the mixture was diluted with EtOAc (100 mL) and water (100 mL). The organic phase was washed with water, then brine, dried (Na₂SO₄), concentrated in vacuo and purified by reverse phase chromatography (MeCN/H₂O with 0.1% TFA) to give the TFA salt of 7-(4-methoxybenzylamino)-3-(5-amino-2-chloro-4-fluorophenyl)-1-ethyl-1,6-naphthyridin-2(1H)-one. The salt was treated with satd. NaHCO₃(15 mL), allowed to stand and the resulting solid was collected by filtration, washed with water and dried in vacuo to give 7-(4-methoxybenzylamino)-3-(5-amino-2-chloro-4-fluorophenyl)-1-ethyl-1,6-naphthyridin-2(1H)-one (901 mg, 36% yield). ¹H NMR (400 MHz, DMSO-d₆), δ 1.10 (t, 3H), 3.69 (s, 3H), 4.05-4.00 (m, 2H), 4.50-4.45 (s, 2H), 5.30 (s, 2H), 6.28 (s, 1H), 6.71-6.69 (m, 1H), 6.87-6.85 (m, 2H), 7.18-7.15 (m, 1H), 7.28-7.26 (m, 2H), 7.52 (s, 1H), 7.64 (s, 1H), 8.36 (s, 1H); MS (ES-API) m/z: 453.2 [M+H]⁺.

Example A10

Example B2 (0.701 g, 3.53 mmol), Example C2 (0.817 g, 3.53 mmol), and 40% KF on alumina (3.59 g, 24.7 mmol) were combined in DMA (5 mL) and the mixture was sonicated for 2 h. The mixture was diluted with EtOAc (10 mL), the solids removed via filtration through diatomaceous earth and washed with EtOAc. The filtrate was washed with water (2×), and brine, dried (Na₂SO₄), concentrated in vacuo and purified by silica gel chromatography (EtOAc\Hex) to afford 3-(5-amino-2-chloro-4-fluorophenyl)-7-chloro-1-isopropyl-1,6-naphthyridin-2(1H)-one (0.99 g, 77% yield) as a white foam. ¹H NMR (400 MHz, DMSO-d₆): δ 8.87 (s, 1H), 8.10 (s, 1H), 7.96 (s, 1H), 7.38 (d, J=11.2 Hz, 1H), 6.89 (d, J=9.2 Hz, 1H), 5.55 (s, 2H), 5.23 (br s, 1H), 1.65 (d, J=6.4 Hz, 6H); MS (ESI) m/z: 366.0 [M+H]⁺.

Example A11

(4-Methoxyphenyl)-N-methylmethanamine (0.56 g, 3.75 mmol) and DBU (0.52 mL, 3.75 mmol) were added to a solution of Example A10 (0.98 g, 2.68 mmol) in NMP (10 mL) and the mixture was heated under Ar at 155° C. for 24 h. The mixture was cooled to RT, poured into water (50 mL) and extracted with EtOAc (2×). The combined organics were washed with brine, dried (Na₂SO₄), concentrated in vacuo and purified by chromatography (EtOAc\DCM) to afford 7-(4-methoxybenzyl)(methyl)amino)-3-(5-amino-2-chloro-4-fluorophenyl)-1-isopropyl-1,6-naphthyridin-2(1H)-one (0.78 g, 60% yield) as a white foam. MS (ESI) m/z: 481.0 (M+H⁺)

TFA (5.55 g, 48.7 mmol) was added to 7-((4-methoxybenzyl)(methyl)amino)-3-(5-amino-2-chloro-4-fluorophenyl)-1-isopropyl-1,6-naphthyridin-2(1H)-one (0.78 g, 1.62 mmol) and the reaction was stirred for 90 min at RT. Water (50 mL) was added and the reaction mixture was carefully treated with solid Na₂CO₃until it was faintly basic. The solution was extracted with EtOAc (2×), and the combined organics were washed with brine, dried (Na₂SO₄), concentrated in vacuo and purified by silica gel chromatography (MeOH/DCM) to afford 3-(5-amino-2-chloro-4-fluorophenyl)-1-isopropyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (0.42 g, 72% yield) as a white amorphous solid. ¹H NMR (400 MHz, DMSO-d₆): δ 8.34 (s, 1H), 7.60 (s, 1H), 7.17 (d, J=11.2 Hz, 1H), 6.95 (q, J=4.8 Hz, 1H), 6.71 (d, J=9.6 Hz, 1H), 6.41 (s, 1H), 5.30 (s, 2H), 5.08 (br s, 1H), 2.84 (d, J=4.8 Hz, 3H), 1.49 (d, J=6.8 Hz, 6H); MS (ESI) m/z: 361.0 [M+H]⁺.

Example A12

A suspension of Example A3 (1.50 g, 4.26 mmol) in 2-methoxyethylamine (3 mL, 34.51 mm) was heated at 120° C. for 12 h. The reaction mixture was diluted with water and extracted with EtOAc (3×). The combined organic layers were washed with brine, dried (Na₂SO₄), and concentrated to provide 3-(5-amino-2-chloro-4-fluorophenyl)-1-ethyl-7-(2-methoxyethylamino)-1,6-naphthyridin-2(1H)-one (1.56 g, 94% yield) as a white solid. ¹H NMR (400 MHz, DMSO-d₆): δ 8.36 (s, 1H), 7.65 (s, 1H), 7.18 (d, J=11 Hz, 1H), 7.03 (m, 1H), 6.72 (d, J=9.5 Hz, 1H), 6.38 (s, 1H), 5.30 (s, 2H), 4.07 (m, 2H), 3.47 (m, 4H), 3.25 (s, 3H), 1.20 (s, 3H); MS (ESI) m/z: 391.1 [M+H]⁺.

Example A13

A mixture of Example C5 (2.191 g, 7.94 mmol), Example B1 (1.538 g, 8.33 mmol) and KF on alumina (40 wt %) (9.22 g, 63.5 mmol) in DMA (40 mL) was sonicated for 2 h. The mixture was filtered through a shallow bed of silica gel and rinsed well with EtOAc. The filtrate was washed with satd. NaHCO₃(1×), 5% LiCl (2×), then brine (1×), dried (MgSO₄), and concentrated to dryness to afford 3-(5-amino-2-bromo-4-fluorophenyl)-7-chloro-1-ethyl-1,6-naphthyridin-2(1H)-one (2.793 g, 89% yield) as a brown solid. ¹H NMR (400 MHz, DMSO-d₆): δ 8.77 (s, 1H), 8.00 (s, 1H), 7.74 (s, 1H), 7.37 (d, 1H), 6.77 (d, 1H), 5.45 (s, 2H), 4.27 (q, 2H), 1.20 (t, 3H); MS (ESI) m/z: 398.0 [M+H]⁺.

Example A14

A suspension of Example A13 (1.50 g, 3.78 mmol) in dioxane (15 mL) was treated with methylamine (40% in water) (26.4 mL, 303 mmol) in a pressure tube and heated to 100° C. overnight. The mixture was cooled to RT, treated with a large amount of brine, then diluted with EtOAc until all of the solids dissolved. The layers were separated, the aqueous layer extracted with additional EtOAc (1×) and the combined organics were washed with satd. NaHCO₃(1×), dried (MgSO₄) and concentrated to dryness. The resulting solid was suspended in MeCN/H₂O, frozen and lyophilized to afford 3-(5-amino-2-bromo-4-fluorophenyl)-1-ethyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (1.32 g, 89% yield) as a light brown solid. ¹H NMR (400 MHz, DMSO-d₆): δ 8.37 (s, 1H), 7.62 (s, 1H), 7.30 (d, 1H), 6.99 (q, 1H), 6.73 (d, 1H), 6.21 (s, 1H), 5.33 (s, 2H), 4.11 (q, 2H), 2.84 (d, 3H), 1.19 (t, 3H); MS (ESI) m/z: 393.0 [M+H]⁺.

Example A15

To a solution of Example A3 (1.00 g, 2.84 mmol) in DMF (10 mL) was added N,N-dimethylethanediamine (0.250 g, 2.84 mmol) and the resulting reaction mixture was heated at 100° C. for 36 h. The reaction mixture was diluted with water and extracted with EtOAc (3×). The combined organic layers were washed with brine, dried (MgSO₄), and the solvent evaporated. The residue was crystallized from IPA to provide 3-(5-amino-2-chloro-4-fluorophenyl)-7-(2-(dimethylamino)ethylamino)-1-ethyl-1,6-naphthyridin-2(1H)-one (0.98 g, 85% yield) as a white solid. ¹H NMR (400 MHz, DMSO-d₆): δ 8.36 (s, 1H), 7.64 (s, 1H), 7.17 (d, J=11 Hz, 1H), 6.84 (m, 1H), 6.72 (d, J=9 Hz, 1H), 6.37 (s, 1H), 5.30 (s, 2H), 4.08 (m, 2H), 3.40 (m, 2H), 2.41 (t, J=6 Hz, 2H), 2.20 (s, 6H), 1.18 (t, J=6 Hz, 3H); MS (ESI) m/z: 404.2 [M+H]⁺.

Example A16

To a solution of Example A3 (1.00 g, 2.84 mmol) in DMF (10 mL) was added N,N-dimethylpropaneamine (0.870 g, 8.52 mmol) and the resulting reaction mixture was heated at 100° C. for 36 h. The mixture was diluted with water and extracted with EtOAc (3×). The combined organic layers were washed with brine, dried (MgSO₄), and the solvent evaporated to provide 3-(5-amino-2-chloro-4-fluorophenyl)-7-(3-(dimethylamino)propylamino)-1-ethyl-1,6-naphthyridin-2(1H)-one (1.10 g, 93% yield) as an orange foam. ¹H NMR (400 MHz, DMSO-d₆): δ 8.36 (s, 1H), 7.64 (s, 1H), 7.20 (d, J=11 Hz, 1H), 7.03 (m, 1H), 6.76 (d, J=9 Hz, 1H), 6.27 (s, 1H), 5.30 (s, 2H), 4.08 (m, 2H), 3.30 (m, 2H), 2.26 (t, J=6 Hz, 2H), 2.05 (m, 6H), 1.66 (m, 2H), 1.18 (t, J=6 Hz, 3H); MS (ESI) m/z: 418.2.2 [M+H]⁺.

Example A17

A solution of Example A3 (0.25 g, 0.710 mmol) in THF (6 mL) was treated with dimethylamine (2M in THF, 2.84 mL, 5.68 mmol) and heated at 80° C. overnight. Additional dimethylamine (2M in THF, 5.68 mL, 11.36 mmol) was added over 3 days and the reaction mixture was heated at 80° C. The mixture was partitioned between DCM and satd. NaHCO₃and extracted with DCM (3×). The combined organic extracts were dried (MgSO₄) and evaporated. The crude product was purified by silica gel chromatography (EtOAc/Hex) to give 3-(5-amino-2-chloro-4-fluorophenyl)-7-(dimethylamino)-1-ethyl-1,6-naphthyridin-2(1H)-one (0.21 g, 82% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.45 (s, 1H), 7.69 (s, 1H), 7.18 (d, 1H), 6.73 (d, 1H), 6.29 (s, 1H), 5.31 (br s, 2H), 4.21 (q, 2H), 3.14 (s, 6H), 1.18 (t, 3H); MS (ESI) m/z: 361.1 [M+H]⁺.

Example A18

To a solution of Example B1 (19 g, 103.3 mmol) and Example C4 (20.3 g, 103.3 mmol) in DMF (150 mL) was added K₂CO₃(28.5 g, 206.6 mmol), and the reaction mixture was heated at 90° C. overnight. The mixture was poured into water (300 mL), stirred at RT for 10 min and the resulting precipitate collected by filtration, washed with water and dried to give 3-(5-amino-2,4-difluoro-phenyl)-7-chloro-1-ethyl-1H-[1,6]naphthyridin-2-one (22 g, 65% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.76 (s, 1H), 8.07 (s, 1H), 7.71 (s, 1H), 7.11 (t, J=10.4 Hz, 1H), 8.84 (dd, J=10.0, 7.6 Hz, 1H), 5.09 (s, 2H), 4.25 (q, J=6.8 Hz, 2H), 1.19 (t, J=6.8 Hz, 3H).

Example A19

To a suspension of Example A18 (0.180 g, 0.536 mmol) in dioxane (5 mL) was added 2-methoxyethylamine (0.462 mL, 5.36 mmol) and the mixture was heated at 100° C. for 20 h. Solvent from the reaction mixture was evaporated and the residue was stirred with water (50 mL). The solids were filtered, washed and dried to provide 3-(5-amino-2,4-difluorophenyl)-1-ethyl-7-(2-methoxyethylamino)-1,6-naphthyridin-2(1H)-one (0.185 g, 92% yield) as a white solid. MS (ESI) m/z: 375.1 [M+H]⁺.

Example A20

A mixture of Example B2 (5 g, 25 mmol), Example C1 (5.3 g, 25 mmol) and Cs₂CO₃(21.4 g, 66 mmol) in DMF (50 mL) was heated at 100° C. overnight. The solid was removed by filtration and the filter cake was washed with DMF. The organics were concentrated and the residue was purified by silica gel chromatography (EtOAc/pet ether) to give 3-(5-amino-4-fluoro-2-methylphenyl)-7-chloro-1-isopropyl-1,6-naphthyridin-2(1H)-one (1.7 g, 20% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.69 (s, 1H), 7.84 (s, 1H), 7.78 (s, 1H), 6.87-6.84 (d, J=12.4 Hz, 1H), 6.61-6.58 (d, J=9.6 Hz, 1H), 5.11-5.08 (br s, 1H), 4.93 (s, 2H), 1.93 (s, 3H), 1.50-1.48 (d, J=6.8 Hz, 6H); MS (ESI) m/z: 346 [M+H]

Example A21

A mixture of Example A20 and (4-methoxy-benzyl)-methyl-amine (4.5 g, 30 mmol) was heated to 180° C. under a N₂atmosphere for 8 h. The excess (4-methoxy-benzyl)-methyl-amine was removed under reduced pressure to give the crude product, which was suspended in 50% aqueous acetic acid and stirred for 30 min. The mixture was extracted with EtOAc (3×) and the combined organics were washed with brine, dried (MgSO₄) and concentrated to give 7-((4-methoxybenzyl)(methyl)amino)-3-(5-amino-4-fluoro-2-methylphenyl)-1-isopropyl-1,6-naphthyridin-2(1H)-one (1.0 g, 76.9% yield), which was used in the next step without further purification.

To a solution of 7-((4-methoxybenzyl)(methyl)amino)-3-(5-amino-4-fluoro-2-methylphenyl)-1-isopropyl-1,6-naphthyridin-2(1H)-one (1.0 g, 2.2 mmol) in DCM (10 mL) was added TFA (3 mL) at RT. The resulting mixture was stirred at RT for 6 h, then washed with H₂O (6×). The combined aqueous layers were neutralized with NH₃H₂O, extracted with DCM (3×) and the combined organic layers were washed with brine, dried (Na₂SO₄), filtered and concentrated to give 3-(5-amino-4-fluoro-2-methylphenyl)-1-isopropyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (0.5 g, 66.8% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.41 (s, 1H), 7.60 (s, 1H), 6.95 (m, 1H), 6.90 (d, J=12.4 Hz, 1H), 6.65 (d, J=9.2 Hz, 1H), 6.50 (s, 1H), 5.21 (br s, 1H), 4.95 (s, 2H), 2.92 (d, J=4.8 Hz, 3H), 2.02 (s, 3H), 1.58 (d, J=6.8 Hz, 6H); MS (ESI) m/z: 341.2[M+H]⁺.

Example A22

Example A3 (0.50 g, 1.420 mmol), 4-aminotetrahydropyran (0.431 g, 4.26 mmol) and TEA (0.394 mL, 2.84 mmol) were combined in NMP (5 mL) and the mixture was heated at 180° C. under microwave irradiation for 6 h. Additional 4-aminotetrahydropyran (0.2 mL) was added and the mixture was heated at 180° C. under microwave irradiation for 3 h more. The mixture was quenched with water and extracted with EtOAc (3×). The organics were washed with 5% LiCl, then brine, dried (Na₂SO₄), concentrated to dryness and purified by silica gel column chromatography (MeOH/DCM) to obtain 3-(5-amino-2-chloro-4-fluorophenyl)-1-ethyl-7-(tetrahydro-2H-pyran-4-ylamino)-1,6-naphthyridin-2(1H)-one (0.31 g, 52% yield). MS (ESI) m/z: 417.1 [M+H]⁺.

Example A23

Example A3 (0.4 g, 1.14 mmol) and 3-methoxypropylamine (0.5 g, 5.69 mmol) were combined in NMP (5 mL) and heated at 120° C. for 24 h. The mixture was poured in water, extracted with EtOAc (2×) and the combined organics were washed with brine, dried (Na₂SO₄), concentrated to dryness and purified by silica gel chromatography (MeOH/DCM) to afford 3-(5-amino-2-chloro-4-fluorophenyl)-1-ethyl-7-(3-methoxypropylamino)-1,6-naphthyridin-2(1H)-one (409 mg, 89% yield) as an orange solid. ¹H NMR (400 MHz, DMSO-d₆): δ 8.36 (s, 1H), 7.64 (s, 1H), 7.18 (d, J=11.2 Hz, 1H), 7.04 (t, J=5.6 Hz, 1H), 7.20 (d, J=8.8 Hz, 1H), 6.27 (s, 1H), 5.30 (s, 2H), 4.09 (q, J=6.8 Hz, 2H), 3.41-3.30 (m, 4H), 3.23 (s, 3H), 1.80-1.73 (m, 2H), 1.18 (t, J=6.8 Hz, 3H); MS (ESI) m/z: 405.1 [M+H]⁺.

Example A24

A solution of Example C4 (5 g, 23.2 mmol), Example B2 (4.6 g, 23.2 mmol) and Cs₂CO₃(15 g, 2 eq) in DMF were heated at 80° C. overnight. The mixture was poured into water and extracted with EtOAc. The combined organic layers were washed with brine, dried (Na₂SO₄), concentrated to dryness and purified by silica gel chromatography to give 3-(5-amino-2,4-difluorophenyl)-7-chloro-1-isopropyl-1,6-naphthyridin-2(1H)-one (4 g, 49% yield). MS (ESI) m/z: 350.2 [M+H]⁺.

Example A25

A mixture of Example A24 (4 g, 11.5 mmol) and methylamine (30 mL) was heated to 100° C. in a sealed vessel for 12 h, then cooled to RT. The mixture was concentrated and residue was washed with EtOAc to give 3-(5-amino-2,4-difluorophenyl)-1-isopropyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (3.5 g, 90% yield). ¹H NMR (400 MHz, DMSO-d₆), δ 8.40 (s, 1H), 7.70 (s, 1H), 7.05 (t, J=10 Hz, 1H), 6.98 (m, 1H), 6.81 (t, J=7.6 Hz, 1H), 6.45 (s, 1H), 5.10 (br s, 1H), 5.06 (s, 2H), 2.87 (d, J=4.8 Hz, 3H), 1.53 (d, J=6.8 Hz, 6H); MS (ESI) m/z: 345.1 [M+H]⁺.

Example A26

Example A3 (0.150 g, 0.426 mmol) and (S)-(+)-1-methoxy-2-propylamine (0.228 g, 2.56 mmol) were combined in NMP (4 mL) and heated in the microwave at 180° C. for 18 h. After cooling, the reaction was diluted with satd. LiCl and extracted with EtOAc (2×). The combined organics were washed successively with satd. LiCl (1×), H₂O (1×), and brine (1×), dried (MgSO₄), filtered and evaporated. The crude product was purified by silica gel chromatography (EtOAc/Hex) to afford (S)-3-(5-amino-2-chloro-4-fluorophenyl)-1-ethyl-7-(1-methoxypropan-2-ylamino)-1,6-naphthyridin-2(1H)-one (0.13 g, 75% yield). MS (ESI) m/z: 405.1 (M+H⁺), 407.1 (M+2+H⁺).

Example A27

A solution of Example A6 (500 mg, 1.507 mmol) and cyclopropylamine (860 mg, 15.07 mmol) in EtOH (15 mL) was heated at 100° C. in a sealed vessel. After 20 h the reaction mixture was treated with additional cyclopropylamine (860 mg, 15.07 mmol) and catalytic DMAP (10 mg) and heated at 100° C. for 23 h, then 115° C. for 10 days. The mixture was cooled to RT, concentrated to dryness and the resulting residue dissolved in EtOAc (30 mL) and washed successively with water (30 mL), satd. NaHCO₃(30 mL) and brine (30 mL). The organic phase was dried over Na₂SO₄, concentrated to dryness and purified by reverse phase chromatography (MeCN/H₂O with 0.1% TFA). The aqueous solution was treated with satd. NaHCO₃(5 mL) and allowed to stand. A solid formed which was collected by filtration to yield 3-(5-amino-4-fluoro-2-methylphenyl)-7-(cyclopropylamino)-1-ethyl-1,6-naphthyridin-2(1H)-one (124 mg, 23% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.36 (s, 1H), 7.60 (s, 1H), 7.28 (s, 1H), 6.83 (d, 1H), 6.58 (d, 1H), 6.38 (s, 1H), 4.87 (s, 2H), 4.18-4.12 (m, 2H), 2.59 (m, 1H), 1.94 (s, 3H), 1.21 (t, 3H), 0.75 (m, 2H), 0.47 (m, 2H); MS (ES-API) m/z: 353.1 [M+H]⁺.

Example A28

To a suspension of Example A6 (0.500 g, 1.507 mmol) in dioxane (10 mL) was added 2-methoxyethylamine (2 mL, 23.22 mmol) and the mixture was heated at 100° C. for 40 h. Solvent from the reaction mixture was evaporated and the residue was diluted with water (50 mL) and extracted with EtOAc (3×). The combined organic layers were washed with brine, dried, and the solvent evaporated to provide 3-(5-amino-4-fluoro-2-methylphenyl)-1-ethyl-7-(2-methoxyethylamino)-1,6-naphthyridin-2(1H)-one (405 mg, 73% yield) as an orange-yellow solid. MS (ESI) m/z: 371.2 [M+H]⁺.

Example A29

A solution of Example A13 (0.500 g, 1.261 mmol) and 2-methoxy ethylamine (0.947 g, 12.61 mmol) in NMP (5 mL) was heated at 120° C. After 4 h the reaction mixture was cooled and partitioned between EtOAc and water. The organic layer was separated and the aqueous layer was extracted with additional EtOAc (1×). The combined organic layers were washed with brine, dried and the solvent evaporated to provide 3-(5-amino-2-bromo-4-fluorophenyl)-1-ethyl-7-(2-methoxyethylamino)-1,6-naphthyridin-2(1H)-one (0.486 g, 89% yield) as brownish mass. ¹H NMR (400 MHz, DMSO-d₆): δ 8.37 (s, 1H), 7.62 (s, 1H), 7.30 (d, J=12 Hz, 1H), 7.04 (m, 1H), 6.72 (d, J=10 Hz, 1H) 6.39 (s, 1H), 5.33 (s, 2H), 4.08 (m, 2H), 3.50 (m, 4H), 3.27 (s, 3H), 1.18 (t, J=6 Hz, 3H); MS (ESI) m/z: 435.1/437.1 [M+H]⁺.

Example A30

To a solution of Example A3 (2.0 g, 5.7 mmol) in NMP (10 mL) was added tetrahydro-furan-3-ylamine (1.5 g, 17.2 mmol) and DBU (1.7 g, 11.4 mmol). Nitrogen was bubbled through the mixture for 5 min and then it was heated in the microwave at 180° C. for 1 h. The reaction mixture was cooled to RT, poured into water and extracted with EtOAc (3×). The combined organics were washed with brine, dried over Na₂SO₄, concentrated under reduced pressure and purified by silica gel chromatography to give 3-(5-amino-2-chloro-4-fluorophenyl)-1-ethyl-7-(tetrahydrofuran-3-ylamino)-1,6-naphthyridin-2(1H)-one (0.57 g, 25% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.39 (s, 1H), 7.66 (s, 1H), 7.27 (d, J=6.4 Hz, 1H), 7.18 (d, J=11.2 Hz, 1H), 6.72 (d, J=9.6 Hz, 1H), 6.33 (s, 1H), 5.31 (s, 2H), 4.46-4.42 (m, 1H), 4.08 (q, J=6.8 Hz, 2H), 3.89-3.81 (m, 2H), 3.75-3.69 (m, 1H), 3.55-3.52 (m, 1H), 2.22-2.17 (m, 1H), 1.83-1.79 (m, 1H), 1.20 (t, J=6.8 Hz, 3H).

Example A31

Example A13 (0.165 g, 0.416 mmol) and 2-(thiomethyl)ethylamine (0.38 g, 4.16 mmol) were combined in NMP (2 mL) and the solution was heated in the microwave at 180° C. for 5 h. The mixture was poured into water (30 mL) and the resultant suspension was filtered, washed with water and dried to afford 3-(5-amino-2-bromo-4-fluorophenyl)-1-ethyl-7-(2-(methylthio)ethylamino)-1,6-naphthyridin-2(1H)-one (0.19 g, 100% yield) as an off-white solid. ¹H NMR (400 MHz, DMSO-d₆): δ 8.37 (s, 1H), 7.62 (s, 1H), 7.30 (d, J=10.8 Hz, 1H), 7.15 (t, J=6.8 Hz, 1H), 7.32 (d, J=8.8 Hz, 1H), 6.33 (s, 1H), 5.33 (s, 2H), 4.09 (q, J=7.2 Hz, 2H), 3.53 (q, J=7.2 Hz, 2H), 2.66 (t, J=6.8 Hz, 2H), 2.10 (s, 3H), 1.18 (t, J=7.2 Hz, 3H); MS (ESI) m/z: 451.1 [M+H]⁺.

Example A32

Example A13 (2.5 g, 6.35 mmol) and 4-methoxybenzylamine (50 mL) were combined and heated at 140° C. overnight. The reaction mixture was cooled to RT, then poured into water. The resulting solid was collected via filtration, dried and purified by silica gel chromatography (EtOAc/pet ether) to give 7-(4-methoxybenzylamino)-3-(5-amino-2-bromo-4-fluorophenyl)-1-ethyl-1,6-naphthyridin-2(1H)-one (2.5 g, 81% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.35 (s, 1H), 7.59 (s, 1H), 7.51-7.48 (t, J=5.6 Hz, 1H), 7.29 (s, 1H), 7.26 (d, J=8.4 Hz, 2H), 6.85 (d, J=8.4 Hz, 2H), 6.70 (d, J=9.6 Hz, 1H), 6.27 (s, 1H), 5.31 (s, 2H), 4.45 (d, J=5.6 Hz, 2H), 4.06-4.01 (q, J=6.8 Hz, 2H), 3.53 (s, 3H), 1.10-1.07 (t, J=6.8 Hz, 3H).

Example A33

Example A32 (2.5 g, 13.8 mmol) in TFA (30 mL) was stirred at 50-60° C. for 2 days. The mixture was concentrated, dissolved in EtOAc (100 mL) and washed with satd. NaHCO₃(3×), then brine (3×). The organic layer was dried with Na₂SO₄, and concentrated to obtain crude product. Hydrochloric acid (6 M, 100 mL) was added to the residue and the solution was washed with EtOAc (3×). The aqueous layer was neutralized with satd. NaHCO₃and then extracted with EtOAc (3×). The organic layers were washed with brine (1×), dried and concentrated to give 7-amino-3-(5-amino-2-bromo-4-fluorophenyl)-1-ethyl-1,6-naphthyridin-2(1H)-one (1 g, 53% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.56 (s, 1H), 7.79 (s, 1H), 7.73 (s, 2H), 7.37 (d, J=10.8 Hz, 1H), 6.77 (s, 1H), 6.73 (d, J=7.6 Hz, 1H), 5.89-5.03 (br s, 2H), 4.14-4.08 (q, J=6.8 Hz, 2H), 1.25-1.21 (t, J=6.8 Hz, 3H).

Example A34

A solution of Example A6 (2.5 g, 7.5 mmol) and 4-methoxybenzylamine (30 mL) was refluxed at 140° C. for 2 h. After cooling to RT, the reaction mixture was poured into a 20% aq. solution of acetic acid and stirred for 0.5 h. The mixture was filtered to provide 7-(4-methoxybenzylamino)-3-(5-amino-4-fluoro-2-methylphenyl)-1-ethyl-1,6-naphthyridin-2(1H)-one.

TFA (2 mL, 26.9 mmol) was added to a solution of 7-(4-methoxybenzylamino)-3-(5-amino-4-fluoro-2-methylphenyl)-1-ethyl-1,6-naphthyridin-2(1H)-one in DCM (10 mL) and the reaction mixture was refluxed at 50° C. for 2 h. After cooling to RT, the reaction mixture was washed with water and the combined aqueous layers were neutralized with satd. NaHCO₃. The aqueous layer was extracted with EtOAc (3×) and the extracts were dried (Na₂SO₄) and concentrated to give 7-amino-3-(5-amino-4-fluoro-2-methylphenyl)-1-ethyl-1,6-naphthyridin-2(1H)-one (0.9 g, 46% yield, over 2 steps). ¹H NMR (300 MHz, DMSO-d₆): δ 8.30 (s, 1H), 7.56 (s, 1H), 6.83 (d, J=12.3 Hz, 1H), 6.57 (d, J=9.6 Hz, 1H), 6.40 (s, 2H), 6.32 (s, 1H), 4.85 (s, 2H), 4.07 (q, J=6.9 Hz, 2H), 1.94 (s, 3H), 1.19 (t, J=6.9 Hz, 3H); MS (ESI) m/z: 313.3 [M+H]⁺.

Example A35

Example A9 (2 g, 4.4 mmol) in TFA (10 mL) was stirred at 60° C. overnight, cooled to RT, added to water (10 mL) and extracted with EtOAc (3×). The combined organics layers were washed with brine, dried over Na₂SO₄, concentrated in vacuo, and purified by silica gel chromatography to afford 7-amino-3-(5-amino-2-chloro-4-fluorophenyl)-1-ethyl-1,6-naphthyridin-2(1H)-one (870 mg, 59% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.35 (s, 1H), 7.68 (s, 1H), 7.21 (d, J=10.8 Hz, 1H), 6.75 (d, J=9.6 Hz, 1H), 6.52 (s, 2H), 6.35 (s, 1H), 5.33 (s, 2H), 4.09 (q, J=6.8 Hz, 2H), 1.22 (t, J=6.8 Hz, 3H); MS (ESI) m/z: 333.2 [M+H]⁺.

Example A36

A solution of Example A18 (1 g, 3 mmol) in (4-methoxyphenyl)methanamine (10 mL) was heated at 130° C. overnight. The mixture was cooled to RT, poured into a mixture of 1:1 acetic acid and water (10 mL), stirred for 30 minutes, and extracted with EtOAc (2×). The combined organic layers were washed with brine, dried over Na₂SO₄, filtered, and the filtrate concentrated to give a crude product which was purified by silica gel chromatography to give 7-(4-methoxybenzylamino)-3-(5-amino-2,4-difluorophenyl)-1-ethyl-1,6-naphthyridin-2(1H)-one (1 g, 69% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.40 (s, 1H), 7.74 (s, 1H), 7.57-7.54 (m, 1H), 7.30 (d, J=8.4 Hz, 2H), 7.08-7.03 (m, 1H), 6.90 (d, J=4.4 Hz, 2H), 6.78-6.72 (m, 1H), 6.30 (s, 1H), 5.02 (s, 2H), 4.49 (d, J=6.0 Hz, 2H), 4.11-4.09 (q, J=7.2 Hz, 2H), 3.72 (s, 3H), 1.14-1.11 (t, J=6.8 Hz, 3H).

Example A37

To a solution of Example B3 (1 g, 5.5 mmol) and Example C5 (1.53 g, 5.5 mmol) in DMA (10 mL) was added KF/Al₂O₃(3 g), and the mixture was stirred at RT for 10 min. The reaction mixture was filtered, the filtrate concentrated and the residue poured into water. The resulting solid was collected via filtration, washed with water, dried under vacuum and washed with MTBE to give 3-(5-amino-2-bromo-4-fluoro-phenyl)-7-chloro-1-methyl-1H-[1,6]naphthyridin-2-one (1.5 g, 67% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.76 (s, 1H), 7.99 (s, 1H), 7.66 (s, 1H), 7.37 (d, J=11.2, 1H), 6.75 (d, J=9.6 Hz, 1H), 5.44 (s, 2H), 3.62 (s, 3H).

Example A38

A solution of Example B1 (6.0 g, 0.033 mol), ethyl 2-(3-amino-4-fluorophenyl)acetate (6.4 g, 0.033 mol) and K₂CO₃(9.17 g, 0.066 mol) in DMF (100 mL) was heated to 80° C. overnight. The reaction mixture was poured into the water and extracted with EtOAc (3×). The combined extracts were washed with brine (3×), dried (MgSO₄), concentrated in vacuo and purified by chromatography to provide 3-(3-amino-4-fluorophenyl)-7-chloro-1-ethyl-1,6-naphthyridin-2(1H)-one (7.0 g, 68% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.75 (s, 1H), 8.07 (s, 1H), 7.67 (s, 1H), 7.13 (dd, J=8.8, 2.0 Hz, 1H), 7.02 (dd, J=11.6, 8.4 Hz, 1H), 6.80 (m, 1H), 5.20 (s, 2H), 4.25 (q, J=6.8 Hz, 2H), 1.19 (t, J=6.8 Hz, 3H); MS (ESI) m/z: 318.2 [M+H]⁺.

Example A39

Using the 2-step procedure of Example A4 and A5, Example A38 (0.85 g, 2.7 mmol) and 4-methoxybenzylmethylamine (10 mL) were combined to provide 3-(3-amino-4-fluorophenyl)-1-ethyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (0.45 g, 32% yield, 2 steps). ¹H NMR (300 MHz, DMSO-d₆): δ 8.40 (s, 1H), 7.77 (s, 1H), 7.11 (d, J=9.0 Hz, 1H), 6.95 (m, 2H), 6.76 (m, 1H), 6.19 (s, 1H), 5.09 (s, 2H), 4.14 (m, 2H), 2.85 (br s, 3H), 1.20 (t, J=6.0, 3H); MS (ESI) m/z (M+H⁺): 313.3.

Example A40

KF/Al₂O₃(40 wt %, 10 g, 69 mmol) was added to a solution of Example B2 (6 g, 30 mmol) and ethyl (3-amino-4-fluorophenyl)acetate (6 g, 30 mmol) in DMA (80 mL) and stirred at RT for 1 h. The mixture was filtered and the filtrate was concentrated under vacuum. The residue was poured into water, and the precipitate was collected by filtration, washed with Et₂O, and dried in vacuo to give 3-(3-amino-4-fluorophenyl)-7-chloro-1-isopropyl-1,6-naphthyridin-2(1H)-one (7 g, 70% yield). ¹H NMR (400 Hz, DMSO-d₆): δ 8.71 (s, 1H), 8.00 (s, 1H), 7.76 (s, 1H), 7.11 (dd, J=9.2, 2.4 Hz, 1H), 7.05 (dd, J=11.6, 8.4 Hz, 1H), 6.76 (m, 1H), 5.18 (s, 2H), 5.15 (m, 1H), 1.52 (d, J=7.2 Hz, 1H); MS (ESI) m/z: 332.0 [M+H]⁺.

A mixture of 3-(3-amino-4-fluorophenyl)-7-chloro-1-isopropyl-1,6-naphthyridin-2(1H)-one (4 g, 12.1 mmol) and (4-methoxybenzyl)methylamine (15 mL) was degassed under reduced pressure, then heated to 180° C. under N₂for 4 h. After cooling, the reaction mixture was diluted with Et₂O. The precipitate was filtered, washed with Et₂O and dried in vacuo to give 3-(3-amino-4-fluoro-phenyl)-1-isopropyl-7-[(4-methoxybenzyl)-methyl-amino]-1H-[1,6]naphthyridin-2-one (5.3 g) as a solid contaminated with (4-methoxybenzyl)methylamine HCl salt.

The above prepared 3-(3-amino-4-fluoro-phenyl)-1-isopropyl-7-[(4-methoxy-benzyl)-methyl-amino]-1H-[1,6]naphthyridin-2-one (5.3 g) was combined with TFA (50 mL) in DCM (150 mL) and heated at reflux overnight. The volatiles were removed under reduced pressure, the residue dissolved in 10% HCl and washed with EtOAc (3×). The aqueous layer was made basic (pH=11), extracted with EtOAc and the combined organics were dried (Na₂SO₄) and concentrated to give 3-(3-amino-4-fluoro-phenyl)-1-isopropyl-7-methylamino-1H-[1,6]naphthyridin-2-one (1.26 g, 32% yield over two steps). ¹H NMR (400 MHz, DMSO-d₆): δ 8.36 (s, 1H), 7.70 (s, 1H), 7.06 (dd, J=8.4, 2.0 Hz, 1H), 6.94 (dd, J=11.6, 8.4 Hz, 1H), 6.88 (m, 1H), 6.72 (m, 1H), 6.39 (s, 1H), 5.07 (m, 1H), 5.06 (s, 2H), 2.83 (d, J=4.8 Hz, 1H), 1.51 (d, J=6.8 Hz, 6H); MS (ESI) m/z: 327.1 [M+H]⁺.

Example A41

Example C2 (3 g, 12.9 mmol), Example B3 (2.2 g, 12.9 mmol) and KF/Al₂O₃(40%, 6 g, 41 mmol) were combined in DMA (40 mL) and the resultant mixture was stirred at RT for 1 h. The mixture was filtered and the filtrate was concentrated in vacuo. The residue was washed with Et₂O to give 3-(5-amino-2-chloro-4-fluorophenyl)-7-chloro-1-methyl-1,6-naphthyridin-2(1H)-one (2.6 g, 60% yield). ¹H NMR (300 MHz, DMSO-d₆): δ 8.74 (s, 1H), 8.00 (s, 1H), 7.63 (s, 1H), 7.23 (d, J=11.2 Hz, 1H), 6.75 (d, J=9.2 Hz, 1H), 5.40 (s, 2H), 3.60 (s, 3H); MS (ESI) m/z: 338.1[M+H]⁺.

A mixture of 3-(5-amino-2-chloro-4-fluorophenyl)-7-chloro-1-methyl-1,6-naphthyridin-2(1H)-one (2.5 g, 7.4 mmol) and 4-methoxy-N-methylbenzylamine (4 mL) was heated to 180° C. under N₂for 3 h. After cooling, the reaction mixture was diluted with Et₂O. The precipitate was filtered, washed with water, and dried to give 7-((4-methoxybenzyl)(methyl)amino)-3-(5-amino-2-chloro-4-fluorophenyl)-1-methyl-1,6-naphthyridin-2(1H)-one (3 g, 89% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.47 (s, 1H), 7.77 (s, 1H) 7.22 (m, 2H), 7.17 (d, J=8.0 Hz, 2H), 6.86 (d, J=8.4 Hz, 2H), 5.86 (d, J=9.6 Hz, 1H), 6.30 (s, 1H), 5.32 (s, 2H) 4.87 (s, 1H), 3.72 (s, 3H), 3.52 (s, 3H), 3.09 (s, 3H); MS (ESI) m/z: 453.2[M+H]⁺.

A solution of 7-((4-methoxybenzyl)(methyl)amino)-3-(5-amino-2-chloro-4-fluorophenyl)-1-methyl-1,6-naphthyridin-2(1H)-one (3 g, 6.6 mmol) in DCM (50 mL) was treated with TFA (20 mL) and the mixture was heated to reflux overnight. The mixture was concentrated under reduced pressure, the residue was dissolved in 10% HCl (50 mL), washed with EtOAc, neutralized with satd. NaHCO₃and extracted with EtOAc (3×). The combined organics were washed with brine, dried (Na₂SO₄) and concentrated in vacuo to give 3-(5-amino-2-chloro-4-fluorophenyl)-1-methyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (1.6 g, 72% yield) ¹H NMR (300 MHz, DMSO-d₆): δ 8.36 (s, 1H), 7.66 (s, 1H), 7.17 (d, J=10.8 Hz, 1H), 7.05 (m, 1H), 6.71 (d, J=9.6 Hz, 1), 6.15 (s, 1H), 5.30 (s, 2H), 3.47 (s, 3H), 3.42 (s, 1H), 2.84 (d, J=4.4 Hz, 3H); MS (ESI) m/z: 333.1 [M+H]⁺

Example A42

Example B3 (3.2 g, 18.8 mmol), Example C6 (4.0 g, 18.8 mmol) and Cs₂CO₃(12.3 g, 37.6 mmol) were combined in DMF (80 mL) and heated to 80° C. for 4 h. The reaction mixture was poured into water (600 mL) and the precipitate was collected by filtration and dried under reduced pressure to give 3-(5-amino-2-chlorophenyl)-7-chloro-1-methyl-1,6-naphthyridin-2(1H)-one (5.0 g, 83% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.74 (s, 1H), 7.97 (s, 1H), 7.63 (s, 1H), 7.09 (d, J=8.4 Hz, 1H), 6.57 (dd, J=8.4 Hz, 2.8 Hz, 1H), 6.52 (s, 1H), 5.31 (s, 2H), 3.60 (s, 3H).

A mixture of 3-(5-amino-2-chlorophenyl)-7-chloro-1-methyl-1,6-naphthyridin-2(1H)-one (5 g, 15.67 mmol), 4-methoxybenzylmethylamine (3.6 g, 23.5 mmol) and DBU (3.7 g, 23.5 mmol) in NMP (80 mL) was heated at 180° C. under N₂for 4 h. The reaction was cooled to RT and poured into water (600 mL). The precipitate was collected by filtration and dried in vacuo to give 7-((4-methoxybenzyl)(methyl)amino)-3-(5-amino-2-chlorophenyl)-1-methyl-1,6-naphthyridin-2(1H)-one (6.5 g, 95% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.46 (s, 1H), 7.68 (s, 1H), 7.16 (d, J=8.8 Hz, 2H), 7.06 (d, J=8.4 Hz, 1H), 6.85 (d, J=8.8 Hz, 2H), 6.54-6.51 (m, 2H), 6.29 (s, 1H), 5.23 (s, 2H), 4.85 (s, 2H), 3.69 (s, 3H), 3.51 (s, 3H), 3.07 (s, 3H).

TFA (10 mL, 134 mmol) was added to a solution of 7-((4-methoxybenzyl)(methyl)amino)-3-(5-amino-2-chlorophenyl)-1-methyl-1,6-naphthyridin-2(1H)-one (4 g, 9.2 mmol) in DCM (50 mL) and heated to reflux for 3 h. The reaction mixture was concentrated under reduced pressure, dissolved in HCl, washed with EtOAc (3×), neutralized with satd. Na₂CO₃and extracted with EtOAc (3×). The combined extracts were washed with brine, dried over Na₂SO₄, concentrated under reduced pressure and purified by chromatography to give 3-(5-amino-2-chlorophenyl)-1-methyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (1.7 g, 58% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.36 (s, 1H), 7.63 (s, 1H), 7.06-7.00 (m, 2H), 6.54-6.50 (m, 2H), 6.14 (s, 1H), 5.21 (s, 2H), 3.48 (s, 3H), 2.84 (d, J=4.8 Hz, 3H); MS (ESI) m/z: 314.9 [M+H]⁺.

Example A43

A solution of Example B3 (2 g, 11.8 mmol) in DMA (40 mL) was treated with Example C1 (2.5 g, 11.8 mmol), followed by KF/Al₂O₃(40 wt %, 10 g, 68 mmol) and stirred at RT for 2 h. The mixture was filtered, the filtrate poured into water and the precipitate was collected by filtration and dried to give 3-(5-amino-4-fluoro-2-methylphenyl)-7-chloro-1-methyl-1,6-naphthyridin-2(1H)-one (2.5 g, 69% yield). ¹H NMR (300 MHz, DMSO-d₆): δ 8.72 (s, 1H), 7.90 (s, 1H), 7.62 (s, 1H), 6.88 (d, J=12.3 Hz, 1H), 6.60 (d, J=6 Hz, 1H), 4.95 (s, 2H), 3.60 (s, 3H), 1.95 (s, 3H); MS (ESI) m/z: 318.0 [M+H]⁺.

3-(5-amino-4-fluoro-2-methylphenyl)-7-chloro-1-methyl-1,6-naphthyridin-2(1H)-one (1.36 g, 4.28 mmol, 1.00 eq), 4-methoxy-N-methylbenzylamine (0.971 g, 6.42 mmol, 1.50 eq) and DBU (0.960 mL, 6.42 mmol, 1.50 eq) were combined in NMP (20 mL) and heated at 180° C. under Ar overnight. The mixture was cooled to RT and poured onto H₂O (200 mL). The resulting solids were collected by filtration, rinsed very well with H₂O, dried on the filter to dampness and then dissolved in EtOAc. The solution was dried (MgSO₄), filtered and evaporated to afford 7-((4-methoxybenzyl)(methyl)amino)-3-(5-amino-4-fluoro-2-methylphenyl)-1-methyl-1,6-naphthyridin-2(1H)-one (1.86 g, 100% yield) as a brittle brown foam which was used as is in the next reaction. ¹H NMR (400 MHz, DMSO-d₆): δ 8.45 (s, 1H), 7.63 (s, 1H), 7.16 (d, J=8.8 Hz, 2H), 6.85 (d, J=8.8 Hz, 2H), 6.86-6.82 (m, 1H), 6.57 (d, J=9.6 Hz, 1H), 6.29 (s, 1H), 4.88 (br s, 2H), 4.85 (s, 2H), 3.69 (s, 3H), 3.52 (s, 3H), 3.07 (s, 3H), 1.94 (s, 3H); MS (ESI) m/z: 433.3 [M+H]⁺.

7-((4-methoxybenzyl)(methyl)amino)-3-(5-amino-4-fluoro-2-methylphenyl)-1-methyl-1,6-naphthyridin-2(1H)-one (1.86 g, 4.3 mmol) and TFA (9.5 mL, 121 mmol) were combined and stirred at RT overnight. The mixture was treated slowly with 2M Na₂CO₃until the mixture was just faintly basic, then stirred at RT for 1 h. The solids were collected by filtration, washed thoroughly with H₂O, dried partially in the air and then under high vacuum at 65° C. The crude product was purified by flash column chromatography (THF/EtOAc) to afford 3-(5-amino-4-fluoro-2-methylphenyl)-1-methyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (0.86 g, 64% yield) as an off-white solid. ¹H NMR (400 MHz, DMSO-d₆): δ 8.35 (s, 1H), 7.58 (s, 1H), 6.99 (q, J=4.8 Hz, 1H), 6.56 (d, J=12.0 Hz, 1H), 6.56 (d, J=9.2 Hz, 1H), 6.15 (s, 1H), 4.87 (br s, 2H), 3.48 (s, 3H), 2.84 (d, J=5.2 Hz, 3H), 1.94 (s, 3H); MS (ESI) m/z: 313.2 [M+H]⁺.

Example A44

Example B3 (2 g, 9.3 mmol), Example C4 (1.6 g, 9.3 mmol) and KF/Al₂O₃(40%, 5 g, 34.4 mmol) were combined in DMA and stirred for 10 min. The reaction mixture was poured into water and extracted with EtOAc. The combined organic layers were washed with brine, dried (Na₂SO₄) and concentrated in vacuo. The residue was purified by chromatography to give 3-(5-amino-2,4-difluorophenyl)-7-chloro-1-methyl-1,6-naphthyridin-2(1H)-one (2 g, 68% yield). ¹H NMR (300 MHz, DMSO-d₆): δ 8.41 (s, 1H), 7.73 (s, 1H), 7.06-7.03 (m, 1H), 6.81-6.75 (m, 1H), 6.15 (s, 1H), 4.98 (s, 2H), 3.48 (s, 3H); MS (ESI) m/z: 322.7 [M+H]⁺.

3-(5-Amino-2,4-difluorophenyl)-7-chloro-1-methyl-1,6-naphthyridin-2(1H)-one (2.4 g, 7.5 mmol) and 4-methoxy-N-methylbenzylamine (10 mL) were combined in a sealed vessel and heated to 200° C. overnight. The volatiles were removed in vacuo and the residue was purified by column chromatography to give 7-(4-methoxybenzyl)(methyl)amino)-3-(5-amino-2,4-difluorophenyl)-1-methyl-1,6-naphthyridin-2(1H)-one (3 g, 91% yield), which was used in the next step without further purification.

A solution of 7-(4-methoxybenzyl)(methyl)amino)-3-(5-amino-2,4-difluorophenyl)-1-methyl-1,6-naphthyridin-2(1H)-one (3 g, 6.8 mmol) in DCM (100 mL) was treated with TFA (20 mL) and stirred at RT for 6 h. The mixture was extracted with water and the combined aqueous layers were neutralized with NH₃H₂O. The precipitate was collected by filtration and dried to give 3-(5-amino-2,4-difluorophenyl)-1-methyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (661 mg, 30% yield). ¹H NMR (300 MHz, DMSO-d₆): δ 8.39 (s, 1H), 7.78 (s, 1H), 7.08-6.93 (m, 2H), 6.80 (dd, J=10.2, 8.1 Hz, 1H), 6.16 (s, 1H), 5.00 (s, 2H), 3.50 (s, 3H), 2.84 (d, J=4.8 Hz, 3H); MS (ESI) m/z: 317.0 [M+H]⁺.

Example A45

A solution of 4-chloro-2-fluoroaniline (5.0 g, 34.3 mmol) in acetic acid (3 mL) was treated with acetic anhydride (6.45 mL, 68.7 mmol) and stirred at RT for 2 h. The mixture was poured onto ice water, stirred for 2 h and the resulting solid collected via filtration and dried to afford N-(4-chloro-2-fluorophenyl)acetamide (6.12 g, 95% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 9.80 (s, 1H), 7.91 (t, J=8.7 Hz, 1H), 7.45 (dd, J=10.8, 2.4 Hz, 1H), 7.22 (d, J=8.9 Hz, 1H), 2.07 (s, 3H).

A −78° C. solution of N-(4-chloro-2-fluorophenyl)acetamide (2.00 g, 10.66 mmol) in THF (40 mL), under Ar, was treated with butyl lithium (16.66 mL, 26.7 mmol), stirred at −78° C. for 2.5 h, treated slowly with DMF (1.651 mL, 21.32 mmol), stirred for 15 min at −78° C. and slowly warmed to RT. The mixture was stirred for 2 h, treated with satd. NH₄Cl, the layers separated and the aqueous layer extracted with EtOAc (1×). The combined organics were washed with brine, dried over Na₂SO₄, concentrated to dryness and purified via silica gel chromatography (EtOAc/Hex) to afford N-(4-chloro-2-fluoro-3-formylphenyl)acetamide (1.1 g, 48% yield) as an off-white solid. MS (ESI) m/z: 216.0 [M+H]⁺.

A 0° C. solution of N-(4-chloro-2-fluoro-3-formylphenyl)acetamide (1.1 g, 5.10 mmol) in MeOH (10 mL) was treated portion-wise with sodium borohydride (0.193 g, 5.10 mmol), stirred at 0° C. for 0.5 h, then warmed to RT and concentrated to dryness. The residue was treated with water, extracted with EtOAc (2×) and the combined organics were washed with brine, dried over Na₂SO₄and concentrated to dryness to afford N-(4-chloro-2-fluoro-3-(hydroxymethyl)phenyl)acetamide (1.05 g, 95% yield) as a white solid. MS (ESI) m/z: 218.0 [M+H]⁺.

A 0° C. of N-(4-chloro-2-fluoro-3-(hydroxymethyl)phenyl)acetamide (1.05 g, 4.82 mmol) and TEA (1.003 mL, 7.24 mmol) in DCM (30 mL) was treated slowly with methanesulfonyl chloride (0.414 mL, 5.31 mmol), warmed to RT and stirred for 2 h. The mixture was treated with satd. NaHCO₃, extracted with DCM (2×) and the combined organics were washed with brine, dried over Na₂SO₄and concentrated to dryness to afford 3-acetamido-6-chloro-2-fluorobenzyl methanesulfonate (1.31 g, 74% yield) as an off-white solid. MS (ESI) m/z: 296.0 [M+H]⁺.

A solution of 3-acetamido-6-chloro-2-fluorobenzyl methanesulfonate (1.31 g, 3.54 mmol) in DMSO (10 mL) was treated with sodium cyanide (0.868 g, 17.72 mmol), stirred at RT overnight, treated with water and extracted with EtOAc (2×). The combined organics were washed with brine, dried over Na₂SO₄, concentrated to dryness and purified via silica gel chromatography (EtOAc/Hex) to afford N-(4-chloro-3-(cyanomethyl)-2-fluorophenyl)acetamide (630 mg, 78% yield) as a yellow solid. MS (ESI) m/z: 227.0 [M+H]⁺.

HCl gas was bubbled into 0° C. EtOH (30 mL), added to N-(4-chloro-3-(cyanomethyl)-2-fluorophenyl)acetamide (0.28 g, 1.235 mmol) and heated at 80° C. for 7 h. The mixture was cooled to RT, concentrated to dryness and the residue neutralized with satd. NaHCO₃. The mixture was extracted with EtOAc (2×) and the combined organics were washed with brine, dried over Na₂SO₄and purified via silica gel chromatography (EtOAc/Hex) to afford ethyl 2-(3-amino-6-chloro-2-fluorophenyl)acetate (250 mg, 87% yield) as an off-white solid. MS (ESI) m/z: 232.1 [M+H]⁺.

A solution of ethyl 2-(3-amino-6-chloro-2-fluorophenyl)acetate (0.252 g, 1.089 mmol) in DMA (5 mL) was treated with Example B1 (0.201 g, 1.089 mmol) and KF on alumina (40%, 1.107 g, 7.62 mmol) and sonicated for 1 h. The mixture was diluted with EtOAc, filtered through diatomaceous earth and rinsed well with EtOAc. The filtrate was washed with water, then brine, dried over Na₂SO₄and concentrated to dryness to afford crude 3-(3-amino-6-chloro-2-fluorophenyl)-7-chloro-1-ethyl-1,6-naphthyridin-2(1H)-one (450 mg, 117% yield) as a white amorphous solid which was used without further purification. MS (ESI) m/z: 352.0 [M+H]⁺.

A solution of 3-(3-amino-6-chloro-2-fluorophenyl)-7-chloro-1-ethyl-1,6-naphthyridin-2(1H)-one (0.45 g, 1.150 mmol) in dioxane (5 mL) was treated with methylamine (40% in water, 7.14 g, 92 mmol) and heated at 100° C. overnight. The mixture was cooled to RT, treated with brine and extracted with EtOAc (2×). The combined organics were dried over Na₂SO₄, concentrated to dryness and purified via silica gel chromatography (MeOH/DCM) to afford 3-(3-amino-6-chloro-2-fluorophenyl)-1-ethyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (350 mg, 88% yield) as a white amorphous solid. ¹H NMR (500 MHz, DMSO-d₆): δ 8.41 (s, 1H), 7.74 (s, 1H), 7.07 (q, J=4.9 Hz, 1H), 7.03 (dd, J=8.7, 1.3 Hz, 1H), 6.77 (t, J=9.0 Hz, 1H), 6.25 (s, 1H), 5.30 (s, 2H), 4.15-4.13 (q, J=7.0 Hz, 2H), 2.87 (d, J=4.9 Hz, 3H), 1.21 (t, J=7.0 Hz, 3H); MS (ESI) m/z: 347.1 [M+H]⁺.

Example A46

Using the three-step procedure of Example A42, Example B1 (3.5 g, 18.8 mmol), Example C6 (4.0 g, 18.8 mmol), Cs₂CO₃(12.3 g, 37.6 mmol), 4-methoxybenzylmethylamine (3.6 g, 23.5 mmol) and TFA (10 mL, 134 mmol) were combined to provide 3-(5-amino-2-chlorophenyl)-1-ethyl-7-(methylamino)-1,6-naphthyridin-2(1H)-one (1.68 g, 27% yield over 3 steps). ¹H NMR (400 MHz, DMSO-d₆): δ 8.36 (s, 1H), 7.62 (s, 1H), 7.05 (dd, J=7.2, 2.0 Hz, 1H), 6.96 (q, J=4.8 Hz, 1H), 6.54-6.50 (m, 2H), 6.21 (s, 1H), 5.21 (s, 2H), 4.11 (q, J=7.2 Hz, 2H), 2.84 (d, J=4.8 Hz, 3H), 1.18 (t, J=7.2 Hz, 3H); MS (ESI) m/z: 329.2[M+H]⁺.

Example A47

A bi-phasic mixture of Example A4 (1.00 g, 2.142 mmol) in EtOAc (25 mL) and satd. NaHCO₃(25 mL) was treated with isopropenyl chloroformate (516 mg, 4.28 mmol) and stirred vigorously at RT for 3 h. Hexane (10 mL) was added and the resulting solid collected via filtration and dried. The layers of the filtrate were separated, the organic layer washed with brine, dried over Na₂SO₄, concentrated to dryness and combined with the above-isolated solid to afford prop-1-en-2-yl (4-chloro-5-(1-ethyl-7-((4-methoxybenzyl)(methyl)amino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)carbamate (1.168 g, 98% yield). MS (ESI) m/z: 551.2 [M+H]⁺.

Example A48

A biphasic solution of Example A2 (300 mg, 0.919 mmol) in EtOAc (10 mL) and satd. NaHCO₃(10 mL) was treated with isopropenyl chloroformate (138 mg, 1.149 mmol) and stirred at RT for 6 h. Additional isopropenyl chloroformate (50 μL) was added and the mixture stirred at RT overnight. The layers were separated, the organic layer washed with brine, dried over Na₂SO₄and concentrated to dryness to afford prop-1-en-2-yl (5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)carbamate (378 mg, 100% yield). MS (ESI) m/z: 411.2 [M+H]⁺.

Example A49

A 0° C. solution of Example A14 (0.75 g, 1.917 mmol) in a biphasic mixture of 1:1:1 EtOAc/THF/satd. NaHCO₃(90 mL) was treated with isopropenyl chloroformate (0.220 mL, 2.013 mmol), allowed to warm to RT and stirred overnight. Additional isopropenyl chloroformate (0.220 mL, 2.013 mmol) was added, the mixture stirred at RT for 3 h, then placed in the refrigerator overnight. The mixture was extracted with EtOAc (2×) and the combined organics were washed with brine, dried over Na₂SO₄and concentrated to dryness to afford prop-1-en-2-yl (4-bromo-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)carbamate (960 mg, 105% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 9.81 (s, 1H), 8.39 (s, 1H), 7.72-7.61 (m, 3H), 7.04 (m, 1H), 6.23 (s, 1H), 4.72 (d, J=9.5 Hz, 2H), 4.13 (m, 2H), 2.85 (d, J=4.8 Hz, 3H), 1.91 (s, 3H), 1.20 (t, J=7.0 Hz, 3H); MS (ESI) m/z: 475.1 [M+H]⁺.

Example A50

A solution of Example 21 (0.1 g, 0.221 mmol) in pyridine (5 mL) was treated with isopropenyl chloroformate (0.027 mL, 0.243 mmol) and stirred at RT overnight. Water was added and the resulting solid was collected via filtration and dried to afford prop-1-en-2-yl (3-(2-chloro-4-fluoro-5-(3-phenylureido)phenyl)-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)carbamate (105 mg, 89% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 10.82 (s, 1H), 9.10 (s, 1H), 8.72 (d, J=2.6 Hz, 1H), 8.70 (s, 1H), 8.23 (d, J=8.6 Hz, 1H), 7.99 (s, 1H), 7.91 (s, 1H), 7.57 (d, J=11.0 Hz, 1H), 7.41 (dd, J=8.2, 1.2 Hz, 2H), 7.26 (m, 2H), 6.97 (t, J=7.4 Hz, 1H), 4.80-4.79 (m, 2H), 4.21 (q, J=7.1 Hz, 2H), 1.96 (s, 3H), 1.25 (t, J=7.1 Hz, 3H); MS (ESI) m/z: 536.1 [M+H]⁺.

Example A51

A suspension of Example A5 (0.154 g, 0.444 mmol) in EtOAc (2.5 mL) was treated with satd. NaHCO₃(2.5 mL) and isopropenyl chloroformate (0.046 mL, 0.422 mmol) and the biphasic mixture stirred vigorously at RT for 3.5 h. Additional isopropenyl chloroformate (20 μL) was added and the mixture was stirred at RT overnight. The mixture was diluted with additional EtOAc and satd. NaHCO₃and the layers separated. The organic layer was washed with brine, dried over MgSO₄and concentrated to dryness. The resulting residue was dissolved in pyridine (1.5 mL), cooled to 0° C., treated with isopropenyl chloroformate (15 μL) and allowed to warm to RT. The mixture was re-cooled to 0° C., treated with additional isopropenyl chloroformate (7 μL) and allowed to warm to RT. The mixture was once again cooled to 0° C., treated with isopropenyl chloroformate (5 μL), allowed to warm to RT and stirred overnight. The mixture was concentrated to dryness, treated with brine and extracted with EtOAc (2×). The combined organics were dried over MgSO₄, concentrated to dryness and purified via silica gel chromatography (EtOAc/Hex) to afford prop-1-en-2-yl (4-chloro-5-(1-ethyl-7-(methylamino)-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)carbamate (141 mg, 74% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 9.80 (s, 1H), 8.40 (s, 1H), 7.75 (s, 1H), 7.64 (s, 1H), 7.55 (d, J=10.5 Hz, 1H), 7.05 (d, J=5.0 Hz, 1H), 6.23 (s, 1H), 4.73 (m, 2H), 4.13 (q, J=7.1 Hz, 2H), 2.85 (d, J=4.9 Hz, 3H), 1.91 (s, 3H), 1.20 (t, J=7.0 Hz, 3H), MS (ESI) m/z: 431.1 [M+H]⁺.

Example A52

A mixture of Example A10 (200 mg, 0.546 mmol) and pyridine (173 mg, 2.184 mmol) in THF (5 mL) was treated with 3-fluorophenyl isocyanate (90 mg, 0.655 mmol) and stirred at RT overnight. The mixture was treated with water and EtOAc and most of the aqueous layer was removed. DMF was added, the mixture concentrated to dryness and purified via reverse-phase chromatography (MeCN/H₂O with 0.1% TFA). The organics were removed under reduced pressure and the aqueous residue was treated with satd. NaHCO₃and allowed to stand at RT. The resulting solid was collected via filtration and dried to afford 1-(4-chloro-5-(7-chloro-1-isopropyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-(3-fluorophenyl)urea (153 mg, 56% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 9.31 (s, 1H), 8.80 (s, 1H), 8.76 (s, 1H), 8.20 (d, J=8.4 Hz, 1H), 8.04 (s, 1H), 7.84 (s, 1H), 7.59 (d, J=10.9 Hz, 1H), 7.46 (d, J=11.9 Hz, 1H), 7.29 (m, 1H), 7.07 (d, J=8.2 Hz, 1H), 6.79 (m, 1H), 5.12 (m, 1H), 1.52 (d, J=6.6 Hz, 6H); MS (ESI) m/z: 503.1 [M+H]⁺.

Example A53

A suspension of Example A6 (0.161 g, 0.485 mmol) in EtOAc (2.5 mL) was treated with satd. NaHCO₃(2.5 mL) followed by isopropenyl chloroformate (0.080 mL, 0.728 mmol) and the bi-phasic mixture stirred vigorously at RT for 2 h. The layers were separated, the organic layer washed with brine dried over MgSO₄and concentrated to dryness to afford prop-1-en-2-yl (5-(7-chloro-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)carbamate (100% yield assumed). MS (ESI) m/z: 416.1 [M+H]⁺.

Example A54

A solution of Example A6 (0.200 g, 0.603 mmol) and TEA (0.126 mL, 0.904 mmol) in THF (6 mL) was treated with phenyl isocyanate (0.066 mL, 0.603 mmol and stirred at RT overnight. The resulting solid was collected via filtration and dried to afford 1-(5-(7-chloro-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-phenylurea (211 mg, 78% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 9.01 (s, 1H), 8.77 (s, 1H), 8.51 (d, J=2.3 Hz, 1H), 8.01-7.98 (m, 2H), 7.73 (s, 1H), 7.41 (dd, J=8.3, 1.2 Hz, 2H), 7.25 (dd, J=8.5, 7.3 Hz, 2H), 7.17 (d, J=12.2 Hz, 1H), 6.97-6.90 (m, 1H), 4.27 (q, J=7.1 Hz, 2H), 2.07 (s, 3H), 1.21 (t, J=7.0 Hz, 3H); MS (ESI) m/z: 451.1 [M+H]⁺.

Example A55

A mixture of Example A10 (700 mg, 1.911 mmol) and pyridine (605 mg, 7.65 mmol) in THF (15 mL) was treated with phenyl isocyanate (250 mg, 2.103 mmol) and stirred at RT for 19 h. The mixture was diluted with EtOAc, washed with satd. NaHCO₃, then brine, dried over Na₂SO₄, concentrated to dryness and purified via reverse-phase chromatography (MeCN/H₂O with 0.1% TFA). The organics were removed under reduced pressure, the aqueous residue treated with satd. NaHCO₃and allowed to stand at RT. The resulting solid was collected via filtration and dried to afford 1-(4-chloro-5-(7-chloro-1-isopropyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluorophenyl)-3-phenylurea (325 mg, 35% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 9.10 (s, 1H), 8.76 (s, 1H), 8.73 (m, 1H), 8.23 (d, J=8.6 Hz, 1H), 8.04 (s, 1H), 7.84 (s, 1H), 7.58 (d, J=11.0 Hz, 1H), 7.41 (d, J=8.0 Hz, 2H), 7.27 (t, J=7.9 Hz, 2H), 6.97 (t, J=7.4 Hz, 1H), 5.11 (m, 1H), 1.52 (d, J=6.7 Hz, 6H); MS (ESI) m/z: 485.1 [M+H]⁺.

Example A56

A solution of Example A6 (0.200 g, 0.603 mmol) and TEA (0.126 mL, 0.904 mmol) in THF (6 mL) was treated with 3-fluorophenyl isocyanate (0.083 ml, 0.723 mmol) and stirred at RT for 4 h. The mixture was concentrated to dryness and purified via silica gel chromatography (EtOAc/Hex). The material was treated with DCM and the solid collected via filtration. The filtrate was concentrated to dryness, re-purified via silica gel chromatography (MeOH/DCM) and combined with the isolated solid to afford 1-(5-(7-chloro-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-(3-fluorophenyl)urea (88 mg, 31% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 9.23 (s, 1H), 8.77 (s, 1H), 8.58 (d, J=2.3 Hz, 1H), 8.00 (s, 1H), 7.97 (d, J=8.4 Hz, 1H), 7.73 (s, 1H), 7.46 (dt, J=12.0, 2.3 Hz, 1H), 7.28 (m, 1H), 7.18 (d, J=12.2 Hz, 1H), 7.05 (ddd, J=8.2, 2.0, 0.9 Hz, 1H), 6.77 (td, J=8.3, 2.5 Hz, 1H), 4.27 (q, J=7.1 Hz, 2H), 2.07 (s, 3H), 1.21 (t, J=7.0 Hz, 3H); MS (ESI) m/z: 469.1 [M+H]⁺.

Example A57

A mixture of Example A34 (0.3 g, 0.960 mmol), phenyl isocyanate (0.137 g, 1.153 mmol) and TEA (0.134 ml, 0.960 mmol) in THF (5 mL) was stirred at RT for 4 h. The mixture was treated with 30% EtOAc/Hex, stirred for several minutes and the resulting solid was collected via filtration and dried to afford 1-(5-(7-amino-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-phenylurea (350 mg, 84% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 9.01 (s, 1H), 8.47 (s, 1H), 8.34 (s, 1H), 7.93 (d, J=8.5 Hz, 1H), 7.65 (s, 1H), 7.41 (dd, J=8.3, 1.2 Hz, 2H), 7.24-7.26 (m, 2H), 7.12 (d, J=12.2 Hz, 1H), 6.95 (t, J=7.4 Hz, 1H), 6.47 (s, 2H), 6.34 (s, 1H), 4.09 (q, J=7.3 Hz, 2H), 2.06 (s, 3H), 1.20 (t, J=7.0 Hz, 3H); MS (ESI) m/z: 432.1 [M+H]⁺.

A solution of 1-(5-(7-amino-1-ethyl-2-oxo-1,2-dihydro-1,6-naphthyridin-3-yl)-2-fluoro-4-methylphenyl)-3-phenylurea (0.35 g, 0.811 mmol) in pyridine (5 mL) was treated with isopropenyl chloroformate (0.147 g, 1.217 mmol) and stirred at RT for 1 h. Water was added, the mixture stirred for 10 minutes and the resulting solid was collected via filtration and dried to afford prop-1-en-2-yl (1-ethyl-3-(4-fluoro-2-methyl-5-(3-phenylureido)phenyl)-2-oxo-1,2-dihydro-1,6-naphthyridin-7-yl)carbamate (360 mg, 86% yield). MS (ESI) m/z: 516.2 [M+H]⁺.

Example B1

A 0° C. solution of Example C3 (4.4 g, 20 mmol) in MeCN (50 mL) was treated drop-wise with a solution of 65% ethylamine in water (2.7 g, 39 mmol), warmed to RT and stirred. The reaction was concentrated and the residue was washed with water to give ethyl 6-chloro-4-(ethylamino)nicotinate (3.9 g, 91% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.51 (s, 1H), 8.08 (s, 1H), 6.53 (m, 1H), 4.19 (q, J=7.2 Hz, 2H), 2.78 (q, J=7.2 Hz, 2H), 1.28 (t, J=7.2 Hz, 3H), 1.13 (t, J=7.2 Hz, 3H); MS (ESI) m/z: 229.1[M+H]⁺.

A −50° C. solution of ethyl 6-chloro-4-(ethylamino)nicotinate (3.9 g, 17 mmol) in THF (50 mL) was treated with LiAlH₄(3.6 g, 95 mmol), allowed to warm to 0° C. and stirred for 1 h. The mixture was quenched with 10% NaOH (3.6 mL), filtered and the filtrate treated with water and extracted with EtOAc (3×). The combined organics were washed with brine, dried (MgSO₄) and concentrated in vacuo to provide (6-chloro-4-(ethylamino)pyridin-3-yl)methanol (2.5 g, 79% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 7.84 (s, 1H), 6.55 (s, 1H), 6.17 (m, 1H), 5.25 (t, J=5.2 Hz, 1H), 4.44 (q, J=7.2 Hz, 2H), 3.23 (m, 2H), 1.23 (t, J=7.2 Hz, 3H).

To a solution of (6-chloro-4-(ethylamino)pyridin-3-yl)methanol (2.5 g, 13.4 mmol) in DCM (30 mL) was added MnO₂(5.8 g, 67 mmol) and the reaction mixture was stirred at RT overnight. The reaction mixture was filtered and the filtrate was concentrated in vacuo to give 6-chloro-4-(ethylamino)nicotinaldehyde (2.2 g, 89% yield). ¹H NMR (400 MHz, CDCl₃): δ 9.82 (s, 1H), 8.51 (br s, 1H), 8.27 (s, 1H), 6.56 (s, 1H), 3.28 (m, 2H), 1.31 (t, J=7.2 Hz, 3H); MS (ESI) m/z: 185.0 [M+H]⁺.

Example B2

Using the three-step procedure of Example B1, Example C3 (20 g, 91 mmol) and isopropylamine (60% in water, 18 g, 182 mmol) were converted to 6-chloro-4-(isopropylamino)nicotinaldehyde (16 g, 81% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 9.82 (s, 1H), 8.43-8.39 (m, 2H), 6.83 (s, 1H), 3.84 (m, 1H), 1.17 (d, J=6.4 Hz, 6H).

Example B3

A 0° C. solution of ethyl 4,6-dichloronicotinate (5 g, 22.8 mmol) in MeCN (30 mL) was treated drop-wise with aqueous methylamine (65%, 5.2 g, 45.6 mmol), warmed to RT and stirred for 8 h. The mixture was concentrated to dryness, the residue suspended in H₂O and extracted with EtOAc (3×). The combined extracts were washed with brine, dried (MgSO₄) and concentrated to give ethyl 6-chloro-4-(methylamino)nicotinate (4 g, 82% yield), which was used in the next step without further purification. ¹H NMR (300 MHz, DMSO-d₆): δ 8.48 (s, 1H), 8.04 (d, J=4.5 Hz, 1H), 6.71 (s, 1H), 4.27 (q, J=6.9 Hz, 2H), 2.85 (d, J=5.1 Hz, 3H), 1.29 (t, J=6.9 Hz, 3H).

A 0° C. solution of ethyl 6-chloro-4-(methylamino)nicotinate (4 g, 18.7 mmol) in THF (40 mL), under a N₂atmosphere, was treated portion-wise with LiAlH₄(1.4 g, 37.4 mmol), stirred for 20 min, then carefully treated with water followed by 2 N NaOH. The suspension was filtered and the filtrate was concentrated to afford (6-chloro-4-(methylamino)pyridin-3-yl)methanol (2.9 g, 91% yield), which was used in next step without purification. ¹H NMR (400 MHz, DMSO-d₆): δ 7.96 (s, 1H), 6.63 (s, 1H), 6.46 (s, 1H), 5.04 (s, 1H), 4.39 (m, 2H), 2.81-2.68 (m, 3H).

A mixture of (6-chloro-4-(methylamino)pyridin-3-yl)methanol (2.9 g, 16.7 mmol) and MnO₂(11.7 g, 133.6 mmol) in anhydrous DCM (25 mL) was stirred at 30° C. for 6 h. The reaction mixture was cooled to RT and filtered. The filtrate was concentrated in vacuo to give 6-chloro-4-(methylamino)nicotinaldehyde (2.5 g, 87% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 9.83 (s, 1H), 8.52 (br s, 1H), 8.40 (s, 1H), 6.75 (s, 1H), 2.87 (d, J=5.8 Hz, 3H); MS (ESI) m/z: 171.0 [M+H]⁺.

Example C1

To stirring fuming HNO₃(90 wt %, 30.0 mL, 643 mmol) at −15° C. was added 4-fluoro-2-methylphenylacetic acid (15 g, 89.2 mmol) in portions such that the internal temperature remained below −10° C. After completing the addition the reaction was stirred with warming to 5° C. over 15 min. The mixture was poured onto ice (400 g), stirred vigorously until the ice had completely melted and the resulting solid was collected by filtration, rinsed well with H₂O and dried on the filter to afford 2-(4-fluoro-2-methyl-5-nitrophenyl)acetic acid (18.43 g, 97% yield) as a pale yellow solid. ¹H NMR (400 MHz, acetone-d₆): δ 8.06 (d, J=7.6 Hz, 1H), 7.36 (d, J=12.0 Hz, 1H), 3.84 (s, 2H), 2.44 (s, 3H).

2-(4-Fluoro-2-methyl-5-nitrophenyl)acetic acid (18.43 g, 86.5 mmol) and conc. H₂SO₄(4.00 mL) were combined in EtOH (300 mL) and heated at 85° C. for 2.5 h. The mixture was cooled to RT, concentrated, the residue dissolved in MTBE and washed with H₂O (2×), then brine (2×), dried (MgSO₄), and evaporated to afford ethyl 2-(4-fluoro-2-methyl-5-nitrophenyl)acetate (16.79 g, 81% yield) as a dark orange oil which was used without further purification. MS (ESI) m/z: 242.0 (M+H)⁺.

A solution of ethyl 2-(4-fluoro-2-methyl-5-nitrophenyl)acetate (16.79 g, 69.6 mmol) in EtOH (60 mL) was treated with 10% Pd/C (50% wet, 7.41 g, 3.48 mmol) and hydrogenated (3.5 atm) for 2 h. The solids were removed via filtration through diatomaceous earth, rinsed with EtOH and the filtrate was concentrated to afford ethyl 2-(5-amino-4-fluoro-2-methylphenyl)acetate (13.18 g, 90% yield) as a brown oil. ¹H NMR (400 MHz, DMSO-d₆): δ 6.80 (d, J=12.4 Hz, 1H), 6.59 (d, J=9.6 Hz, 1H), 4.86 (s, 2H), 4.05 (q, J=7.2 Hz, 2H), 3.46 (s, 2H), 2.05 (s, 3H), 1.17 (t, J=7.2 Hz, 3H); MS (ESI) m/z: 212.2 (M+H)⁺.

Example C2

HNO₃(10.35 g, 98.6 mmol) was added drop-wise to a −10° C. solution of 2-(2-chloro-4-fluorophenyl)acetic acid (16.9 g, 89.6 mmol) in conc. H₂SO₄(60 mL), stirred at 0° C. for 10 min, then carefully poured into ice water. The off-white solid was collected by filtration and dried to give 2-(2-chloro-4-fluoro-5-nitrophenyl)acetic acid (20.5 g, 98% yield). ¹H NMR (400 Hz, DMSO-d₆): δ 12.71 (br s, 1H), 8.33 (d, J=8.0 Hz, 1H), 7.92 (d, J=11.2 Hz, 1H), 3.85 (s, 2H).

A 0° C. solution of 2-(2-chloro-4-fluoro-5-nitrophenyl)acetic acid (20.5 g, 88 mmol) in EtOH (150 mL) was treated with sulfuryl dichloride (21 g, 0.17 mol), then heated to reflux for 1 h. The reaction mixture was concentrated under reduced pressure and treated with satd. Na₂CO₃to pH 7-8. The resultant mixture was extracted with EtOAc (3×) and the combined organic layers were washed with brine, dried (MgSO₄) and concentrated to give ethyl 2-(2-chloro-4-fluoro-5-nitrophenyl)acetate (22.5 g, 98% yield). ¹H NMR (400 Hz, DMSO-d₆): δ 8.32 (d, J=8.0 Hz, 1H), 7.91 (d, J=11.2 Hz, 1H), 4.09 (q, J=7.2 Hz, 2H), 3.92 (s, 2H), 1.17 (t, J=7.2 Hz, 3H).

A solution of ethyl 2-(2-chloro-4-fluoro-5-nitrophenyl)acetate (22.5 g, 86.2 mmol) in EtOH (200 mL) was stirred with Raney Ni (20% slurry in water, 5.0 g, 17 mmol) under a hydrogen atmosphere (30 psi) for 5 h. The catalyst was removed by filtration and the filtrate was concentrated to give ethyl 2-(5-amino-2-chloro-4-fluorophenyl)acetate (19 g, 95% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 7.10 (d, J=11.2 Hz, 1H), 6.71 (d, J=9.2 Hz, 1H), 5.27 (s, 2H), 4.05 (q, J=6.8 Hz, 2H), 3.57 (s, 2H), 1.14 (t, J=6.8 Hz, 3H); MS (ESI) m/z: 232.0 [M+H]⁺.

Example C3

3-Oxo-pentanedioic acid diethyl ester (101 g, 0.5 mmol), triethyl orthoformate (81.4 g, 0.55 mol) and acetic anhydride (102 g, 1 mol) were combined and heated to 120° C. for 2 h. The resulting mixture was cooled to RT and dissolved in DCM (1 L). After further cooling to 0° C., ammonia (30%, 80 mL) was added and the reaction mixture was allowed to warm to RT overnight. The product was extracted with water (2×) and the aqueous layer was acidified to pH 5 with conc. HCl. The precipitate was collected by filtration to afford ethyl 4,6-dihydroxynicotinate (60.0 g, 60% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 7.99 (s, 1H), 5.58 (s, 1H), 4.23 (q, J=6.8, 14.0 Hz, 2H), 1.25 (t, J=7.2 Hz, 3H); MS (ESI) m/z: 184.1 [M+H]⁺.

Ethyl 4,6-dihydroxynicotinate (60 g, 0.328 mol) was added slowly to POCl₃(500 mL), then heated to reflux for 2 h. The resulting mixture was distilled under reduced pressure to remove excess POCl₃. The residue was poured into ice water and stirred for 30 minutes before extracting with EtOAc (3×). The combined extracts were washed with brine, dried (MgSO₄) and concentrated in vacuo to give ethyl 4,6-dichloronicotinate (65 g, 90%, yield). ¹H NMR (300 MHz, DMSO-d₆): δ 8.80 (s, 1H), 7.95 (s, 1H), 4.34 (q, J=6.9 Hz, 2H), 1.31 (t, J=6.9 Hz, 3H); MS (ESI) m/z: 220.1 [M+H]⁺.

Example C4

A 0° C. solution of (2,4-difluoro-phenyl)acetic acid (14.5 g, 0.084 mol) in H₂SO₄(60 mL) was treated drop-wise with 69% HNO₃(6 mL), stirred at 0° C. for 35 min, then poured into ice water. The aqueous layer was extracted with EtOAc, and the organic extracts were washed with brine, dried (Na₂SO₄), concentrated in vacuo and purified by silica gel chromatography to give (2,4-difluoro-5-nitro-phenyl)acetic acid (16 g, 88% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.30 (t, J=8.0 Hz, 1H), 7.68 (m, 1H), 3.75 (s, 2H).

A solution of (2,4-difluoro-5-nitro-phenyl)acetic acid (16 g, 74 mmol) in EtOH (200 mL) and 98% H₂SO₄(14 mL) was refluxed at 80′C for 2.5 h under a N₂atmosphere. The reaction mixture was poured into ice water, and the resultant solution was extracted with Et₂O. The combined organic extracts were washed with brine, dried (Na₂SO₄), concentrated in vacuo and purified by silica gel chromatography to give ethyl 2-(2,4-difluoro-5-nitrophenyl)acetate (16 g, 89% yield). ¹H NMR (300 MHz, DMSO-d₆): δ 8.22 (t, J=8.1 Hz, 1H), 7.55 (t, J=11.1 Hz, 1H), 4.06 (m, 2H), 3.77 (s, 2H), 1.13 (t, J=6.9 Hz, 3H).

A mixture of ethyl 2-(2,4-difluoro-5-nitrophenyl)acetate (16 g, 130 mmol) and 10% Pd/C (1.6 g, 1.5 mmol) in EtOAc was hydrogenated (30 psi) at RT for 12 h. The catalyst was filtered off and the filtrate was evaporated. The residue was purified by column chromatography to give ethyl 2-(5-amino-2,4-difluorophenyl)acetate (14 g, 99% yield). ¹H NMR (300 MHz, DMSO-d₆): δ 6.98 (t, J=9.9 Hz, 1H), 6.70 (t, J=7.8 Hz, 1H), 4.50 (s, 2H), 4.06 (m, 2H), 3.53 (s, 2H), 1.16 (t, J=6.9 Hz, 3H); MS (ESI) m/z: 216.2 [M+H]⁺.

Example C5

Nitric acid (16.00 mL, 322 mmol) was cooled to −15° C. and treated portion-wise with 2-bromo-4-fluorophenylacetic acid (10.00 g, 42.9 mmol) maintaining an internal temperature of −10° C. to −5° C. Once the addition was complete the mixture was warmed to 5° C. over −15 minutes, poured onto ice (200 mL), stirred vigorously until all of the ice melted, and then filtered and rinsed with water. The resulting solid was dissolved in EtOAc, washed with brine, dried (MgSO₄) and concentrated to dryness to afford 2-(2-bromo-4-fluoro-5-nitrophenyl)acetic acid (10.93 g, 92% yield) as a bright yellow solid. ¹H NMR (400 MHz, DMSO-d₆): δ 8.29 (d, 1H), 8.04 (d, 1H), 3.85 (s, 2H).

A solution of 2-(2-bromo-4-fluoro-5-nitrophenyl)acetic acid (5.00 g, 17.98 mmol) in EtOH (100 mL) was treated with concentrated sulfuric acid (0.999 mL, 17.98 mmol) and heated at 85° C. overnight. The mixture was cooled to RT and the EtOH was removed under reduced pressure. The resulting oil was dissolved in MTBE, washed with water (2×) then brine (2×), dried (MgSO₄), and concentrated to dryness. The material was purified by silica gel chromatography (EtOAc/Hex) to afford ethyl 2-(2-bromo-4-fluoro-5-nitrophenyl)acetate (2.679 g, 49% yield) as a yellow oil. ¹H NMR (400 MHz, DMSO-d₆): δ 8.33 (d, 1H), 8.08 (d, 1H), 4.12 (q, 2H), 3.96 (s, 2H), 1.20 (t, 3H); MS (ESI) m/z: 308.0 [M+H]⁺.

A solution of ethyl 2-(2-bromo-4-fluoro-5-nitrophenyl)acetate (2.127 g, 6.95 mmol) in EtOH (70 mL) was treated with iron powder (3.88 g, 69.5 mmol) and satd ammonium chloride (14.48 mL, 69.5 mmol) and heated to 55° C. for 1 h. The mixture was cooled to RT, filtered through a pad of diatomaceous earth, rinsed well with EtOH and the organics concentrated under reduced pressure. The resulting aqueous residue was treated with satd. NaHCO₃, extracted with EtOAc (2×) and the combined organics were washed with water, dried (MgSO₄), and concentrated to afford ethyl 2-(5-amino-2-bromo-4-fluorophenyl)acetate (1.792 g, 93% yield) as an amber oil. ¹H NMR (400 MHz, DMSO-d₆): δ 7.25 (d, 1H), 6.76 (d, 1H), 5.35 (s, 2H), 4.08 (q, 2H), 3.61 (s, 2H), 1.18 (t, 3H); MS (ESI) m/z: 278.0 [M+H]⁺.

Example C6

A mixture of (2-chlorophenyl)acetic acid (15 g, 88 mmol) in conc. H₂SO₄(100 mL) was cooled to −20° C. and treated drop-wise with conc. HNO₃(9.4 g, 97 mmol). The resulting mixture was stirred at −20° C. for 0.5 h, poured into the ice-water, and extracted with EtOAc (3×). The combined organics were washed with brine, dried over Na₂SO₄and concentrated in vacuo to give (2-chloro-5-nitrophenyl)acetic acid (15 g, 79% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.58 (s, 1H), 8.35 (m, 1H), 7.96 (m, 1H), 4.12 (s, 2H).

Thionyl chloride (16.7 g, 0.14 mol) was added drop-wise to a 0° C. solution of (2-chloro-5-nitro-phenyl)acetic acid (15 g, 0.07 mol) in EtOH (300 mL) and the resultant mixture was heated at reflux overnight. The reaction mixture was concentrated under reduced pressure, the residue poured into ice water, and extracted with EtOAc (2×). The combined organics were washed with brine, then satd