Heteroaromatic compounds and their use as dopamine D1 ligands

1. A compound of Formula I:

or a pharmaceutically acceptable salt thereof, wherein:

each of T 1 , T 2 , T 3 , and T 4 is independently selected from the group consisting of H, halogen, —CN, C 1-4 alkyl, C 1-4 haloalkyl, cyclopropyl, fluorocyclopropyl, C 1-4 alkoxy, C 1-4 haloalkoxy, and —C(═O)—O—(C 1-4 alkyl);

X 1 is N or CH;

each of R 1 and R 2 is independently selected from the group consisting of H, halogen, —CN, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 alkoxy, C 1-4 haloalkoxy, and C 3-4 cycloalkyl;

each of R 3 and R 4 is independently selected from the group consisting of H, halogen, —OH, —CN, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 haloalkoxy, C 3-4 cycloalkyl, a 4- to 7-membered heterocycloalkyl, —N(R 5 )(R 6 ), and —OR 8 ;

each of R 5 and R 6 independently is H or selected from the group consisting of C 1-4 alkyl, C 1-4 haloalkyl, and C 3-7 cycloalkyl;

or R 5 and R 6 together with the N atom to which they are attached form a 4- to 7-membered heterocycloalkyl or a 5-membered heteroaryl, each optionally substituted with 1, 2, or 3 substituents each independently selected from the group consisting of halogen, —CN, C 1-4 alkyl, C 1-4 alkoxy, C 3-6 cycloalkyl, C 1-4 haloalkyl, and C 1-4 haloalkoxy;

R 8 is selected from the group consisting of C 1-4 alkyl, C 3-6 cycloalkyl, a 4- to 7-membered heterocycloalkyl, phenyl, and a 5- to 6-membered heteroaryl, each optionally substituted with 1, 2, or 3 substituents each independently selected from the group consisting of halogen, —CN, C 1-4 alkyl, C 1-4 haloalkyl, C 3-6 cycloalkyl, C 1-4 alkoxy, and C 1-4 haloalkoxy;

Q 1 is a moiety of

(“Moiety M 1 ”);

Q 1 or ring Q 1a is an optionally substituted pyridinyl, pyrimidinyl, pyridazinyl, or pyrazinyl;

represents a single bond or double bond;

Z 1 is C;

Z 2 is C or N;

R 9 is C 1-4 alkyl, C 1-4 haloalkyl, C 3-7 cycloalkyl, —CN, —N(R 5 )(R 6 ), C 1-6 alkoxy, C 1-6 haloalkoxy, or C 3-7 cycloalkoxy, wherein each of the C 1-4 alkyl and C 3-7 cycloalkyl is optionally substituted with 1, 2, 3, 4, or 5 substituents each independently selected from the group consisting of halogen, —N(R 5 )(R 6 ), C 1-4 alkyl, C 1-4 haloalkyl, C 3-7 cycloalkyl, C 1-4 alkoxy, and C 1-4 haloalkoxy;

each R 10 is independently selected from the group consisting of halogen, —OH, —CN, —NO 2 , oxo, thiono, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 hydroxylalkyl, C 1-6 alkoxy, C 1-6 haloalkoxy, C 3-7 cycloalkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 6-10 aryl, a 4- to 10-membered heterocycloalkyl, a 5- to 10-membered heteroaryl, (C 3-7 cycloalkyl)-C 1-4 alkyl-, (4- to 10-membered heterocycloalkyl)-C 1-4 alkyl-, (C 6-10 aryl)-C 1-4 alkyl-, (5- to 10-membered heteroaryl)-C 1-4 alkyl-, (5- to 10-membered heteroaryl)-C 2-4 alkenyl-, —N(R 5 )(R 6 ), —N(R 7 )(C(═O)R 8 ), —S(═O) 2 N(R 5 )(R 6 ), —C(═O)—N(R 5 )(R 6 ), —C(═O)—R 8 , —C(═O)—OR 8 , and —OR 8 , wherein each of said C 1-6 alkyl, C 3-7 cycloalkyl, C 6-10 aryl, 4- to 10-membered heterocycloalkyl, 5- to 10-membered heteroaryl, (C 3-7 cycloalkyl)-C 1-4 alkyl-, (4- to 10-membered heterocycloalkyl)-C 1-4 alkyl-, (C 6-10 aryl)-C 1-4 alkyl-, (5- to 10-membered heteroaryl)-C 1-4 alkyl-, and (5- to 10-membered heteroaryl)-C 2-4 alkenyl- is optionally substituted with 1, 2, 3 or 4 substituents each independently selected from the group consisting of halogen, OH, —CN, —NO 2 , C 1-4 alkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy, —N(R 5 )(R 6 ), —S—(C 1-4 alkyl), —S(═O) 2 —(C 1-4 alkyl), C 6-10 aryloxy, (C 6-10 aryl)-C 1-4 alkyloxy- optionally substituted with 1 or 2 C 1-4 alkyl, oxo, —C(═O)H, —C(═O)—C 1-4 alkyl, —CO(═O)O—C 1-4 alkyl, —C(═O)NH 2 , —NHC(═O)H, —NHC(═O)—(C 1-4 alkyl), C 3-7 cycloalkyl, a 5- or 6-membered heteroaryl, C 1-4 haloalkyl, and C 1-4 haloalkoxy;

or R 9 and the adjacent R 10 together with the two ring atoms on ring Q 1a to which they are attached form a fused benzene ring or a fused 5- or 6-membered heteroaryl, each optionally substituted with 1, 2, 3, 4, or 5 independently selected R 10a ;

each R 10a is independently selected from the group consisting of halogen, —OH, —C(═O)OH, —C(═O)—C 1-4 alkyl, —C(═O)—NH 2 , —C(═O)—N(C 1-4 alkyl) 2 , —CN, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 hydroxyalkyl, C 1-4 haloalkyl, and C 1-4 haloalkoxy; and

m is 0, 1, 2, 3, or 4.

2. A compound of Formula I:

or a pharmaceutically acceptable salt thereof, wherein:

each of T 1 , T 2 , T 3 , and T 4 is independently selected from the group consisting of H, halogen, —CN, C 1-4 alkyl, C 1-4 haloalkyl, cyclopropyl, fluorocyclopropyl, C 1-4 alkoxy, C 1-4 haloalkoxy, and —C(═O)—O—(C 1-4 alkyl);

X 1 is N or CH;

each of R 1 and R 2 is independently selected from the group consisting of H, halogen, —CN, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 alkoxy, C 1-4 haloalkoxy, and C 3-4 cycloalkyl;

each of R 3 and R 4 is independently selected from the group consisting of H, halogen, —OH, —CN, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 haloalkoxy, C 3-4 cycloalkyl, a 4- to 7-membered heterocycloalkyl, —N(R 5 )(R 6 ), and —OR 8 ;

each of R 5 and R 6 independently is H or selected from the group consisting of C 1-4 alkyl, C 1-4 haloalkyl, and C 3-7 cycloalkyl;

or R 5 and R 6 together with the N atom to which they are attached form a 4- to 7-membered heterocycloalkyl or a 5-membered heteroaryl, each optionally substituted with 1, 2, or 3 substituents each independently selected from the group consisting of halogen, —CN, C 1-4 alkyl, C 1-4 alkoxy, C 3-6 cycloalkyl, C 1-4 haloalkyl, and C 1-4 haloalkoxy;

R 8 is selected from the group consisting of C 1-4 alkyl, C 3-6 cycloalkyl, a 4- to 7-membered heterocycloalkyl, phenyl, and a 5- to 6-membered heteroaryl, each optionally substituted with 1, 2, or 3 substituents each independently selected from the group consisting of halogen, —CN, C 1-4 alkyl, C 1-4 haloalkyl, C 3-6 cycloalkyl, C 1-4 alkoxy, and C 1-4 haloalkoxy;

Q 1 is a moiety of

(“Moiety M 1 ”);

represents a single bond or double bond;

Z 1 is C;

Z 2 is C or N;

Moiety M 1 is selected from the group consisting of quinolinyl, isoquinolinyl, 1H-imidazo[4,5-c]pyridinyl, imidazo[1,2-a]pyridinyl, 1H-pyrrolo[3,2-c]pyridinyl, imidazo[1,2-a]pyrazinyl, imidazo[2,1-c][1,2,4]triazinyl, imidazo[1,5-a]pyrazinyl, imidazo[1,2-a]pyrimidinyl, 1H-indazolyl, 9H-purinyl, imidazo[1,2-a]pyrimidinyl, [1,2,4]triazolo[1,5-a]pyrimidinyl, isoxazolo[5,4-c]pyridazinyl, isoxazolo[3,4-c]pyridazinyl, and [1,2,4]triazolo[4,3-b]pyridazinyl, each optionally substituted with 1, 2, or 3 R 10 and further optionally substituted with 1 or 2 R 10a ; or wherein Moiety M 1 is selected from the group consisting of pyrimidinyl, pyrazinyl, pyridinyl, pyridazinyl, 1H-pyrazolyl, 1H-pyrrolyl, 4H-pyrazolyl, 3-oxo-2H-pyridazinyl, 1H-2-oxo-pyrimidinyl, 1H-2-oxo-pyridinyl, 2,4(1H,3H)-dioxo-pyrimidinyl, and 1H-2-oxo-pyrazinyl, each substituted with R 9 and further optionally substituted with 1, 2, or 3 R 10 ;

R 9 is C 1-4 alkyl, C 1-4 haloalkyl, C 3-7 cycloalkyl, —CN, —N(R 5 )(R 6 ), C 1-6 alkoxy, C 1-6 haloalkoxy, or C 3-7 cycloalkoxy, wherein each of the C 1-4 alkyl and C 3-7 cycloalkyl is optionally substituted with 1, 2, 3, 4, or 5 substituents each independently selected from the group consisting of halogen, —N(R 5 )(R 6 ), C 1-4 alkyl, C 1-4 haloalkyl, C 3-7 cycloalkyl, C 1-4 alkoxy, and C 1-4 haloalkoxy;

each R 10 is independently selected from the group consisting of halogen, —OH, —CN, —NO 2 , oxo, thiono, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 hydroxylalkyl, C 1-6 alkoxy, C 1-6 haloalkoxy, C 3-7 cycloalkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 6-10 aryl, a 4- to 10-membered heterocycloalkyl, a 5- to 10-membered heteroaryl, (C 3-7 cycloalkyl)-C 1-4 alkyl-, (4- to 10-membered heterocycloalkyl)-C 1-4 alkyl-, (C 6-10 aryl)-C 1-4 alkyl-, (5- to 10-membered heteroaryl)-C 1-4 alkyl-, (5- to 10-membered heteroaryl)-C 2-4 alkenyl-, —N(R 5 )(R 6 ), —N(R 7 )(C(═O)R 8 ), —S(═O) 2 N(R 5 )(R 6 ), —C(═O)—N(R 5 )(R 6 ), —C(═O)—R 8 , —C(═O)—OR 8 , and —OR 8 , wherein each of said C 1-6 alkyl, C 3-7 cycloalkyl, C 6-10 aryl, 4- to 10-membered heterocycloalkyl, 5- to 10-membered heteroaryl, (C 3-7 cycloalkyl)-C 1-4 alkyl-, (4- to 10-membered heterocycloalkyl)-C 1-4 alkyl-, (C 6-10 aryl)-C 1-4 alkyl-, (5- to 10-membered heteroaryl)-C 1-4 alkyl-, and (5- to 10-membered heteroaryl)-C 2-4 alkenyl- is optionally substituted with 1, 2, 3 or 4 substituents each independently selected from the group consisting of halogen, OH, —CN, —NO 2 , C 1-4 alkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy, —N(R 5 )(R 6 ), —S—(C 1-4 alkyl), —S(═O) 2 —(C 1-4 alkyl), C 6-10 aryloxy, (C 6-10 aryl)-C 1-4 alkyloxy- optionally substituted with 1 or 2 C 1-4 alkyl, oxo, —C(═O)H, —C(═O)—C 1-4 alkyl, —CO(═O)O—C 1-4 alkyl, —C(═O)NH 2 , —NHC(═O)H, —NHC(═O)—(C 1-4 alkyl), C 3-7 cycloalkyl, a 5- or 6-membered heteroaryl, C 1-4 haloalkyl, and C 1-4 haloalkoxy;

or R 9 and the adjacent R 10 together with the two ring atoms on ring Q 1a to which they are attached form a fused benzene ring or a fused 5- or 6-membered heteroaryl, each optionally substituted with 1, 2, 3, 4, or 5 independently selected R 10a ;

each R 10a is independently selected from the group consisting of halogen, —OH, —C(═O)OH, —C(═O)—C 1-4 alkyl, —C(═O)—NH 2 , —C(═O)—N(C 1-4 alkyl) 2 , —CN, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 hydroxyalkyl, C 1-4 haloalkyl, and C 1-4 haloalkoxy; and

m is 0, 1, 2, 3, or 4.

3. A compound of Formula I:

or a pharmaceutically acceptable salt thereof, wherein:

each of T 1 , T 2 , T 3 , and T 4 is independently selected from the group consisting of H, halogen, —CN, C 1-4 alkyl, C 1-4 haloalkyl, cyclopropyl, fluorocyclopropyl, C 1-4 alkoxy, C 1-4 haloalkoxy, and —C(═O)—O—(C 1-4 alkyl);

X 1 is N or CH;

each of R 1 and R 2 is independently selected from the group consisting of H, halogen, —CN, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 alkoxy, C 1-4 haloalkoxy, and C 3-4 cycloalkyl;

each of R 3 and R 4 is independently selected from the group consisting of H, halogen, —OH, —CN, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 haloalkoxy, C 3-4 cycloalkyl, a 4- to 7-membered heterocycloalkyl, —N(R 5 )(R 6 ), and —OR 8 ;

each of R 5 and R 6 independently is H or selected from the group consisting of C 1-4 alkyl, C 1-4 haloalkyl, and C 3-7 cycloalkyl;

or R 5 and R 6 together with the N atom to which they are attached form a 4- to 7-membered heterocycloalkyl or a 5-membered heteroaryl, each optionally substituted with 1, 2, or 3 substituents each independently selected from the group consisting of halogen, —CN, C 1-4 alkyl, C 1-4 alkoxy, C 3-6 cycloalkyl, C 1-4 haloalkyl, and C 1-4 haloalkoxy;

R 8 is selected from the group consisting of C 1-4 alkyl, C 3-6 cycloalkyl, a 4- to 7-membered heterocycloalkyl, phenyl, and a 5- to 6-membered heteroaryl, each optionally substituted with 1, 2, or 3 substituents each independently selected from the group consisting of halogen, —CN, C 1-4 alkyl, C 1-4 haloalkyl, C 3-6 cycloalkyl, C 1-4 alkoxy, and C 1-4 haloalkoxy;

Q 1 is a moiety of

(“Moiety M 1 ”);

Moiety M 1 is

R 9 is C 1-4 alkyl, C 1-4 haloalkyl, C 3-7 cycloalkyl, —CN, —N(R 5 )(R 6 ), C 1-6 alkoxy, C 1-6 haloalkoxy, or C 3-7 cycloalkoxy, wherein each of the C 1-4 alkyl and C 3-7 cycloalkyl is optionally substituted with 1, 2, 3, 4, or 5 substituents each independently selected from the group consisting of halogen, —N(R 5 )(R 6 ), C 1-4 alkyl, C 1-4 haloalkyl, C 3-7 cycloalkyl, C 1-4 alkoxy, and C 1-4 haloalkoxy;

each R 10 is independently selected from the group consisting of halogen, —OH, —CN, —NO 2 , oxo, thiono, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 hydroxylalkyl, C 1-6 alkoxy, C 1-6 haloalkoxy, C 3-7 cycloalkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 6-10 aryl, a 4- to 10-membered heterocycloalkyl, a 5- to 10-membered heteroaryl, (C 3-7 cycloalkyl)-C 1-4 alkyl-, (4- to 10-membered heterocycloalkyl)-C 1-4 alkyl-, (C 6-10 aryl)-C 1-4 alkyl-, (5- to 10-membered heteroaryl)-C 1-4 alkyl-, (5- to 10-membered heteroaryl)-C 2-4 alkenyl-, —N(R 5 )(R 6 ), —N(R 7 )(C(═O)R 8 ), —S(═O) 2 N(R 5 )(R 6 ), —C(═O)—N(R 5 )(R 6 ), —C(═O)—R 8 , —C(═O)—OR 8 , and —OR 8 , wherein each of said C 1-6 alkyl, C 3-7 cycloalkyl, C 6-10 aryl, 4- to 10-membered heterocycloalkyl, 5- to 10-membered heteroaryl, (C 3-7 cycloalkyl)-C 1-4 alkyl-, (4- to 10-membered heterocycloalkyl)-C 1-4 alkyl-, (C 6-10 aryl)-C 1-4 alkyl-, (5- to 10-membered heteroaryl)-C 1-4 alkyl-, and (5- to 10-membered heteroaryl)-C 2-4 alkenyl- is optionally substituted with 1, 2, 3 or 4 substituents each independently selected from the group consisting of halogen, OH, —CN, —NO 2 , C 1-4 alkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy, —N(R 5 )(R 6 ), —S—(C 1-4 alkyl), —S(═O) 2 —(C 1-4 alkyl), C 6-10 aryloxy, (C 6-10 aryl)-C 1-4 alkyloxy- optionally substituted with 1 or 2 C 1-4 alkyl, oxo, —C(═O)H, —C(═O)—C 1-4 alkyl, —CO(═O)O—C 1-4 alkyl, —C(═O)NH 2 , —NHC(═O)H, —NHC(═O)—(C 1-4 alkyl), C 3-7 cycloalkyl, a 5- or 6-membered heteroaryl, C 1-4 haloalkyl, and C 1-4 haloalkoxy;

m is 0, 1, or 2;

R 10a is C 1-4 alkyl, C 1-4 haloalkyl, or C 3-7 cycloalkyl; and

t is 0 or 1.

4. A compound of Formula I:

or a pharmaceutically acceptable salt thereof, wherein:

each of T 1 , T 2 , T 3 , and T 4 is independently selected from the group consisting of H, halogen, —CN, C 1-4 alkyl, C 1-4 haloalkyl, cyclopropyl, fluorocyclopropyl, C 1-4 alkoxy, C 1-4 haloalkoxy, and —C(═O)—O—(C 1-4 alkyl);

X 1 is N or CH;

each of R 1 and R 2 is independently selected from the group consisting of H, halogen, —CN, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 alkoxy, C 1-4 haloalkoxy, and C 3-4 cycloalkyl;

each of R 3 and R 4 is independently selected from the group consisting of H, halogen, —OH, —CN, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 haloalkoxy, C 3-4 cycloalkyl, a 4- to 7-membered heterocycloalkyl, —N(R 5 )(R 6 ), and —OR 8 ;

each of R 5 and R 6 independently is H or selected from the group consisting of C 1-4 alkyl, C 1-4 haloalkyl, and C 3-7 cycloalkyl;

or R 5 and R 6 together with the N atom to which they are attached form a 4- to 7-membered heterocycloalkyl or a 5-membered heteroaryl, each optionally substituted with 1, 2, or 3 substituents each independently selected from the group consisting of halogen, —CN, C 1-4 alkyl, C 1-4 alkoxy, C 3-6 cycloalkyl, C 1-4 haloalkyl, and C 1-4 haloalkoxy;

R 8 is selected from the group consisting of C 1-4 alkyl, C 3-6 cycloalkyl, a 4- to 7-membered heterocycloalkyl, phenyl, and a 5- to 6-membered heteroaryl, each optionally substituted with 1, 2, or 3 substituents each independently selected from the group consisting of halogen, —CN, C 1-4 alkyl, C 1-4 haloalkyl, C 3-6 cycloalkyl, C 1-4 alkoxy, and C 1-4 haloalkoxy;

Q 1 is a moiety of

(“Moiety M 1 ”);

Moiety M 1 is

R 9 is C 1-4 alkyl, C 1-4 haloalkyl, C 3-7 cycloalkyl, —CN, —N(R 5 )(R 6 ), C 1-6 alkoxy, C 1-6 haloalkoxy, or C 3-7 cycloalkoxy, wherein each of the C 1-4 alkyl and C 3-7 cycloalkyl is optionally substituted with 1, 2, 3, 4, or 5 substituents each independently selected from the group consisting of halogen, —N(R 5 )(R 6 ), C 1-4 alkyl, C 1-4 haloalkyl, C 3-7 cycloalkyl, C 1-4 alkoxy, and C 1-4 haloalkoxy;

each R 10 is independently selected from the group consisting of halogen, —OH, —CN, —NO 2 , oxo, thiono, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 hydroxylalkyl, C 1-6 alkoxy, C 1-6 haloalkoxy, C 3-7 cycloalkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 6-10 aryl, a 4- to 10-membered heterocycloalkyl, a 5- to 10-membered heteroaryl, (C 3-7 cycloalkyl)-C 1-4 alkyl-, (4- to 10-membered heterocycloalkyl)-C 1-4 alkyl-, (C 6-10 aryl)-C 1-4 alkyl-, (5- to 10-membered heteroaryl)-C 1-4 alkyl-, (5- to 10-membered heteroaryl)-C 2-4 alkenyl-, —N(R 5 )(R 6 ), —N(R 7 )(C(═O)R 8 ), —S(═O) 2 N(R 5 )(R 6 ), —C(═O)—N(R 5 )(R 6 ), —C(═O)—R 8 , —C(═O)—OR 8 , and —OR 8 , wherein each of said C 1-6 alkyl, C 3-7 cycloalkyl, C 6-10 aryl, 4- to 10-membered heterocycloalkyl, 5- to 10-membered heteroaryl, (C 3-7 cycloalkyl)-C 1-4 alkyl-, (4- to 10-membered heterocycloalkyl)-C 1-4 alkyl-, (C 6-10 aryl)-C 1-4 alkyl-, (5- to 10-membered heteroaryl)-C 1-4 alkyl-, and (5- to 10-membered heteroaryl)-C 2-4 alkenyl- is optionally substituted with 1, 2, 3 or 4 substituents each independently selected from the group consisting of halogen, OH, —CN, —NO 2 , C 1-4 alkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy, —N(R 5 )(R 6 ), —S—(C 1-4 alkyl), —S(═O) 2 —(C 1-4 alkyl), C 6-10 aryloxy, (C 6-10 aryl)-C 1-4 alkyloxy- optionally substituted with 1 or 2 C 1-4 alkyl, oxo, —C(═O)H, —C(═O)—C 1-4 alkyl, —CO(═O)O—C 1-4 alkyl, —C(═O)NH 2 , —NHC(═O)H, —NHC(═O)—(C 1-4 alkyl), C 3-7 cycloalkyl, a 5- or 6-membered heteroaryl, C 1-4 haloalkyl, and C 1-4 haloalkoxy; and

R 11 is H, C 1-4 alkyl, C 1-4 haloalkyl, or C 3-7 cycloalkyl.

5. The compound or pharmaceutically acceptable salt according to claim 3 , wherein R 9 is C 1-4 alkyl or —CN; and each R 10 is independently C 1-4 alkyl.

6. A compound selected from:

4-[4-(4,6-dimethylpyrimidin-5-yl)-3-fluorophenoxy]-1H-pyrrolo[3,2-c]pyridine;

(+)-4,6-dimethyl-5-[2-methyl-4-(1H-pyrazolo[4,3-c]pyridin-4-yloxy)phenyl]pyridazin-3(2H)-one;

(−)-4,6-dimethyl-5-[2-methyl-4-(1H-pyrazolo[4,3-c]pyridin-4-yloxy)phenyl]pyridazin-3(2H)-one;

4-[4-(4,6-dimethylpyrimidin-5-yl)-3-methylphenoxy]-1H-pyrrolo[3,2-c]pyridine;

4-[4-(4,6-dimethylpyrimidin-5-yl)-3-methylphenoxy]-1H-pyrazolo[4,3-c]pyridine;

4,6-dimethyl-5-[4-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)phenyl]pyridazin-3(2H)-one;

(−)-1,5-dimethyl-6-[2-methyl-4-(1H-pyrazolo[4,3-c]pyridin-4-yloxy)phenyl]pyrimidine-2,4(1H,3H)-dione;

4,6-dimethyl-5-[2-methyl-4-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)phenyl]pyridazin-3(2H)-one, ENT-1;

4,6-dimethyl-5-[2-methyl-4-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)phenyl]pyridazin-3(2H)-one, ENT-2;

4-[4-(4,6-dimethyl-1-oxidopyrimidin-5-yl)-3-methyl phenoxy]-1H-pyrazolo[4,3-c]pyridine;

6-methyl-5-[2-methyl-4-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)phenyl]imidazo[1,2-a]pyrazine;

4-[4-(4,6-dimethylpyrimidin-5-yl)phenoxy]-1H-pyrrolo[3,2-c]pyridine;

2-(4,6-dimethylpyrimidin-5-yl)-5-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)benzonitrile;

4-[3-chloro-4-(4,6-dimethylpyrimidin-5-yl)phenoxy]-1H-pyrrolo[3,2-c]pyridine;

(−)-1,5-dimethyl-6-[2-methyl-4-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)phenyl]pyrazin-2(1H)-one;

4-[4-(4,6-dimethylpyrimidin-5-yl)-3-fluorophenoxy]-1H-pyrazolo[4,3-c]pyridine;

4-[4-(4,6-dimethylpyrimidin-5-yl)-3-methoxyphenoxy]-1H-pyrazolo[4,3-c]pyridine;

4-[3-chloro-4-(4,6-dimethylpyrimidin-5-yl)phenoxy]-1H-pyrazolo[4,3-c]pyridine;

(+)-1,5-dimethyl-6-[2-methyl-4-(1H-pyrazolo[4,3-c]pyridin-4-yloxy)phenyl]pyrazin-2(1H)-one;

4,6-dimethyl-5-[4-(1H-pyrazolo[4,3-c]pyridin-4-yloxy)phenyl]pyridazin-3(2H)-one; and

1,5-dimethyl-6-[4-(1H-pyrazolo[4,3-c]pyridin-4-yloxy)phenyl]pyrimidine-2,4(1H,3H)-dione,

or a pharmaceutically acceptable salt thereof.

7. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 1 and a pharmaceutically acceptable carrier.

8. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 2 and a pharmaceutically acceptable carrier.

9. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 3 and a pharmaceutically acceptable carrier.

10. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 4 and a pharmaceutically acceptable carrier.

11. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 5 and a pharmaceutically acceptable carrier.

12. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 6 and a pharmaceutically acceptable carrier.

13. A compound that is 4-[4-(4,6-dimethylpyrimidin-5-yl)-3-fluorophenoxy]-1H-pyrrolo[3,2-c]pyridine or a pharmaceutically acceptable salt thereof.

14. The compound according to claim 13 that is 4-[4-(4,6-dimethylpyrimidin-5-yl)-3-fluorophenoxy]-1H-pyrrolo[3,2-c]pyridine.

15. The pharmaceutically acceptable salt according to claim 13 that is a pharmaceutically acceptable salt of 4-[4-(4,6-dimethylpyrimidin-5-yl)-3-fluorophenoxy]-1H-pyrrolo[3,2-c]pyridine.

16. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 13 and a pharmaceutically acceptable carrier.

17. A pharmaceutical composition comprising the compound according to claim 14 and a pharmaceutically acceptable carrier.

18. A pharmaceutical composition comprising the pharmaceutically acceptable salt according to claim 15 and a pharmaceutically acceptable carrier.

19. A compound that is 4-[4-(4,6-dimethylpyrimidin-5-yl)-3-methylphenoxy]-1H-pyrazolo[4,3-c]pyridine or a pharmaceutically acceptable salt thereof.

20. The compound according to claim 19 that is 4-[4-(4,6-dimethylpyrimidin-5-yl)-3-methylphenoxy]-1H-pyrazolo[4,3-c]pyridine.

21. The pharmaceutically acceptable salt according to claim 19 that is a pharmaceutically acceptable salt of 4-[4-(4,6-dimethylpyrimidin-5-yl)-3-methylphenoxy]-1H-pyrazolo[4,3-c]pyridine.

22. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 19 and a pharmaceutically acceptable carrier.

23. A pharmaceutical composition comprising the compound according to claim 20 and a pharmaceutically acceptable carrier.

24. A pharmaceutical composition comprising the pharmaceutically acceptable salt according to claim 21 and a pharmaceutically acceptable carrier.

25. A compound that is (−)-1,5-dimethyl-6-[2-methyl-4-(1H-pyrazolo[4,3-c]pyridin-4-yloxy)phenyl]pyrimidine-2,4(1H,3H)-dione or a pharmaceutically acceptable salt thereof.

26. The compound according to claim 25 that is (−)-1,5-dimethyl-6-[2-methyl-4-(1H-pyrazolo[4,3-c]pyridin-4-yloxy)phenyl]pyrimidine-2,4(1H,3H)-dione.

27. The pharmaceutically acceptable salt according to claim 25 that is a pharmaceutically acceptable salt of (−)-1,5-dimethyl-6-[2-methyl-4-(1H-pyrazolo[4,3-c]pyridin-4-yloxy)phenyl]pyrimidine-2,4(1H,3H)-dione.

28. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 25 and a pharmaceutically acceptable carrier.

29. A pharmaceutical composition comprising the compound according to claim 26 and a pharmaceutically acceptable carrier.

30. A pharmaceutical composition comprising the pharmaceutically acceptable salt according to claim 27 and a pharmaceutically acceptable carrier.

31. A compound that is 4,6-dimethyl-5-[2-methyl-4-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)phenyl]pyridazin-3(2H)-one, ENT-1 or a pharmaceutically acceptable salt thereof.

32. The compound according to claim 31 that is 4,6-dimethyl-5-[2-methyl-4-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)phenyl]pyridazin-3(2H)-one, ENT-1.

33. The pharmaceutically acceptable salt according to claim 31 that is a pharmaceutically acceptable salt of 4,6-dimethyl-5-[2-methyl-4-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)phenyl]pyridazin-3(2H)-one, ENT-1.

34. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 31 and a pharmaceutically acceptable carrier.

35. A pharmaceutical composition comprising the compound according to claim 32 and a pharmaceutically acceptable carrier.

36. A pharmaceutical composition comprising the pharmaceutically acceptable salt according to claim 33 and a pharmaceutically acceptable carrier.

37. A compound that is 4,6-dimethyl-5-[2-methyl-4-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)phenyl]pyridazin-3(2H)-one, ENT-2 or a pharmaceutically acceptable salt thereof.

38. The compound according to claim 31 that is 4,6-dimethyl-5-[2-methyl-4-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)phenyl]pyridazin-3(2H)-one, ENT-2.

39. The pharmaceutically acceptable salt according to claim 31 that is a pharmaceutically acceptable salt of 4,6-dimethyl-5-[2-methyl-4-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)phenyl]pyridazin-3(2H)-one, ENT-2.

40. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 37 and a pharmaceutically acceptable carrier.

41. A pharmaceutical composition comprising the compound according to claim 38 and a pharmaceutically acceptable carrier.

42. A pharmaceutical composition comprising the pharmaceutically acceptable salt according to claim 39 and a pharmaceutically acceptable carrier.

43. A compound that is 2-(4,6-dimethylpyrimidin-5-yl)-5-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)benzonitrile or a pharmaceutically acceptable salt thereof.

44. The compound according to claim 43 that is 2-(4,6-dimethylpyrimidin-5-yl)-5-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)benzonitrile.

45. The pharmaceutically acceptable salt according to claim 43 that is a pharmaceutically acceptable salt of 2-(4,6-dimethylpyrimidin-5-yl)-5-(1H-pyrrolo[3,2-c]pyridin-4-yloxy)benzonitrile.

46. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 43 and a pharmaceutically acceptable carrier.

47. A pharmaceutical composition comprising the compound according to claim 44 and a pharmaceutically acceptable carrier.

48. A pharmaceutical composition comprising the pharmaceutically acceptable salt according to claim 45 and a pharmaceutically acceptable carrier.

49. A compound that is (+)-1,5-dimethyl-6-[2-methyl-4-(1H-pyrazolo[4,3-c]pyridin-4-yloxy)phenyl]pyrazin-2(1H)-one or a pharmaceutically acceptable salt thereof.

50. The compound according to claim 43 that is (+)-1,5-dimethyl-6-[2-methyl-4-(1H-pyrazolo[4,3-c]pyridin-4-yloxy)phenyl]pyrazin-2(1H)-one.

51. The pharmaceutically acceptable salt according to claim 43 that is a pharmaceutically acceptable salt of (+)-1,5-dimethyl-6-[2-methyl-4-(1H-pyrazolo[4,3-c]pyridin-4-yloxy)phenyl]pyrazin-2(1H)-one.

52. A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt according to claim 49 and a pharmaceutically acceptable carrier.

53. A pharmaceutical composition comprising the compound according to claim 50 and a pharmaceutically acceptable carrier.

54. A pharmaceutical composition comprising the pharmaceutically acceptable salt according to claim 51 and a pharmaceutically acceptable carrier.