N-(2-(4-cyanothiazolidin-3-yl)-2-oxoethyl)-quinoline-4-carboxamides

A compound having the structure of Formula (I):

• or a pharmaceutically acceptable salt thereof, wherein:
• X1 is selected from the group consisting of —S—, —S(O)—, and —S(O)2—;
• R1 is selected from the group consisting of hydrogen, halogen, hydroxy, C1-3-alkyl, and C1-6-alkoxy;
• R2 is selected from the group consisting of:
• (a) heterocyclyl containing a total of 4 to 10 ring atoms, wherein the heterocyclyl ring:
• (i) is a saturated, partially saturated, or completely unsaturated monocyclic or fused bicyclic ring, (ii) has one, two, or three nitrogen ring atoms with the remaining ring atoms being carbon, and (iii) is optionally substituted with one or more substituents independently selected from the group consisting of halogen, hydroxy, oxo, cyano, C1-6-alkyl, C3-6-cycloalkyl, C3-6-cycloalkyl-C1-3 alkyl, C1-6-alkoxy, C3-6-cycloalkoxy, C1-3-alkoxy-C1-3-alkyl, C1-3-alkoxy-C2-3-alkoxy, C1-3-alkoxy-C2-3-alkoxy-C1-3-alkyl, C1-3-alkylcarbonyl, C3-6-cycloalkylcarbonyl, C1-3-alkyl-carbonylamino-C1-3-alkyl, C1-3-alkylsulfonyl-C1-3-alkyl, phenyl, tolyl, C1-3-alkoxyphenyl, phenyl-C1-3-alkyl, C1-3-alkoxyphenyl-C1-3-alkyl, azetidinyl, pyrrolidinyl, piperidinyl, morpholinyl, tetrahydrofuranyl, tetrahydropyranyl, and tetrahydrooxepanyl, and wherein:
• (a) the C1-6-alkyl, C3-6-cycloalkyl, C3-6-cycloalkyl-C1-3-alkyl, C1-6-alkoxy, C3-6-cycloalkoxy, C1-3-alkoxy-C1-3-alkyl, C1-3-alkoxy-C2-3-alkoxy, C1-3-alkoxy-C2-3-alkoxy-C1-3-alkyl, C1-3-alkylcarbonyl, C3-6-cycloalkylcarbonyl, C1-3-alkyl-carbonylamino-C1-3-alkyl, C1-3-alkylsulfonyl-C1-3-alkyl, phenyl, tolyl, C1-3-alkoxyphenyl, phenyl-C1-3-alkyl, C1-3-alkoxyphenyl-C1-3-alkyl, azetidinyl, pyrrolidinyl, piperidinyl, morpholinyl, tetrahydrofuranyl, tetrahydropyranyl, and tetrahydrooxepanyl may be further substituted with one or more halogen, and (b) the C1-6-alkyl may be further substituted with one or more hydroxy;
• (b) heterocyclyl containing a total of 5 to 10 ring atoms, wherein the heterocyclyl ring:
• (i) is a saturated, partially saturated, or completely unsaturated monocyclic or fused bicyclic ring, (ii) has (a) one nitrogen ring atom and one oxygen ring atom with the remaining ring atoms being carbon, or (b) one nitrogen ring atom and one sulfur ring atom with the remaining ring atoms being carbon, and (iii) is optionally substituted with one or more substituents independently selected from the group consisting of halogen, cyano, oxo, C1-6-alkyl, C3-6-cycloalkyl, C1-6-alkoxy, C1-3-alkoxy-C1-3-alkyl, C1-3-alkylcarbonyl-C1-3-alkyl, and C1-3-alkylsulfonyl-C1-3-alkyl, and wherein the C1-6-alkyl, C3-6-cycloalkyl, C1-6-alkoxy, C1-3-alkoxy-C1-3-alkyl, C1-3-alkylcarbonyl-C1-3-alkyl, and C1-3-alkylsulfonyl-C1-3-alkyl may be further substituted with one or more halogen;
• and
• (c) spiro heterocyclyl containing a total of 6 to 11 ring atoms, wherein the spiro heterocyclyl:
• (i) contains two saturated rings, (ii) has:
• (a) one or two nitrogen ring atoms with the remaining ring atoms being carbon, (b) one or two nitrogen ring atoms and one or two oxygen ring atoms with the remaining ring atoms being carbon, or (c) one nitrogen ring atom and one sulfur ring atom with the remaining ring atoms being carbon, and (iii) is optionally substituted with one or more substituents independently selected from the group consisting of halogen, oxo, C1-6-alkyl, C1-6-haloalkyl, C1-6-alkoxy, C1-6-haloalkoxy, and C1-6-alkylcarbonyl;
• R3 is selected from the group consisting of hydrogen, halogen, and C1-3-alkyl;
• R4 is selected from the group consisting of hydrogen, halogen, and C1-3-alkyl;
• R5 is selected from the group consisting of hydrogen, halogen, and C1-3-alkyl;
• and
• R6 is selected from the group consisting of hydrogen, halogen, and C1-3-alkyl.