Substituted diazabicycloalkane derivatives

1. A compound of the formula (I):

Z-Ar 1 —Ar 2   (I)

or a pharmaceutically acceptable salt, ester, or amide, thereof, wherein:

Z is a diazabicyclic amine of the formula:

Ar 1 is

Ar 2 is selected from the group consisting of an unsubstituted or substituted 5- or 6-membered heteroaryl ring; unsubstituted or substituted bicyclic heteroaryl ring; 3,4-(methylenedioxy)phenyl; carbazolyl; tetrahydrocarbazolyl; naphthyl; and phenyl; wherein the carbazolyl; tetrahydrocarbazolyl; naphthyl; and phenyl is substituted with 0, 1, 2, or 3 substituents selected from the group consisting of alkenyl, alkoxy, alkoxyalkoxy, alkoxyalkyl, alkoxycarbonyl, alkoxysulfonyl, alkyl, alkylcarbonyl, arylcarbonyl, alkylcarbonyloxy, alkylsulfonyl, alkylthio, alkynyl, carboxy, cyano, formyl, haloalkoxy, haloalkyl, halogen, hydroxy, hydroxyalkyl, mercapto, nitro, —NR A R B , (NR A R B )alkyl, (NR A R B )carbonyl, (NR A R B )sulfonyl, and phenyl;

R 1 is selected from the group consisting of hydrogen, alkenyl, alkyl alkoxycarbonyl, arylalkyl, and heteroarylalkyl;

R 2 at each occurrence is independently selected from the group consisting of hydrogen, alkoxycarbonyl, and alkyl;

R 3 is selected from the group consisting of hydrogen, alkoxy, alkyl, cyano, and hydroxyl;

R A and R B are each independently selected from the group consisting of hydrogen, alkyl, alkylcarbonyl, alkylsulfonyl, arylcarbonyl, formyl and (NR C R D )sulfonyl; and

R C and R D are each independently selected from the group consisting of hydrogen and alkyl.

2. The compound of claim 1 , wherein Ar 2 is selected from the group consisting of benzofuranyl; benzothienyl; carbazolyl; tetrahydrocarbazolyl; furyl; imidazolyl; 3-indolyl; 4-indolyl; 5-indolyl; isoxazolyl; naphthyl; pyrazolyl; pyridazinyl; pyridyl; pyrimidinyl; 2-pyrrolyl, 3-pyrrolyl; quinolinyl; thienyl; 3,4-(methylenedioxy)phenyl; and phenyl; wherein the phenyl is substituted with 0, 1, or 2 substituents selected from the group consisting of alkoxy, alkoxycarbonyl, alkyl, alkylcarbonyl, carboxy, cyano, halogen, haloalkoxy, haloalkyl, hydroxy, nitro, —NR A R B ,(NR A R B )alkyl, (NR A R B )alkoxy, and phenyl.

3. The compound of claim 1 , wherein Ar 2 is selected from the group consisting of:

wherein R 4 is selected from the group consisting of hydrogen, alkoxy, alkoxycarbonyl, alkyl, alkylcarbonyl, carboxy, cyano, halogen, haloalkyl, hydroxy, nitro, —NR A R B , (NR a R B )alkyl, (NR A R B )alkoxy, and phenyl.

4. The compound of claim 1 , wherein Ar 2 is selected from the group consisting of phenyl, para-acetylaminophenyl, meta-aminophenyl, para-aminophenyl, para(2-(diethylamino)ethoxy)phenyl, meta(2-(diethylamino)ethoxy)phenyl, para-(dimethylamino)phenyl, para-bromophenyl, meta-cyanophenyl, para-cyanophenyl, meta-hydroxyphenyl, para-hydroxyphenyl, para-iodophenyl, meta-methylphenyl, para-methylphenyl, 3,5-dimethylphenyl, meta-methoxyphenyl, para-methoxyphenyl, meta-trifluoromethoxyphenyl, meta-nitrophenyl, para-nitrophenyl, and meta-trifluoromethylphenyl.

5. The compound of claim 1 , wherein Z is selected from the group consisting of

6. The compound of claim 5 , wherein Ar 2 is phenyl substituted with 0, 1, or 2 substituents selected from the group consisting of alkoxy, alkoxycarbonyl, alkyl, alkylcarbonyl, carboxy, cyano, halogen, haloalkoxy, haloalkyl, hydroxy, nitro, —NR A R B , (NR A R B )alkyl, (NR A R B )alkoxy, and phenyl.

7. The compound of claim 1 , wherein Z is selected from the group consisting of

8. The compound of claim 7 , wherein Ar 2 is selected from the group consisting of 3-indolyl, 5-indolyl; 1-methyl-3-indolyl, 1-methyl-5-indolyl, 3-methyl-5-indolyl, 3,4-(methylenedioxy)phenyl, and phenyl, wherein the phenyl is substituted with 0, 1, or 2 substituents selected from the group consisting of alkoxy, alkoxycarbonyl, alkyl, alkylcarbonyl, carboxy, cyano, halogen, haloalkoxy, haloalkyl, hydroxy, nitro, —NR A R B , (NR A R B )alkyl, (NR A R B )alkoxy, and phenyl.

9. The compound of claim 1 , wherein Z is

10. The compound of claim 9 , wherein Ar 2 is phenyl substituted with 0, 1, or 2 substituents selected from the group consisting of alkoxy, alkoxycarbonyl, alkyl, alkylcarbonyl, carboxy, cyano, halogen, haloalkoxy, haloalkyl, hydroxy, nitro, —NR A R B , (NR A R B )alkyl, (NR A R B )alkoxy, and phenyl.

11. The compound of claim 9 , wherein Ar 2 is selected from the group consisting of furyl and phenyl, wherein the phenyl is substituted with 0, 1, or 2 substituents selected from the group consisting of alkoxy, alkoxycarbonyl, alkyl, alkylcarbonyl, carboxy, cyano, halogen, haloalkoxy, haloalkyl, hydroxy, nitro, —NR A R B ,(NR A R B )alkyl, (NR A R B )alkoxy, and phenyl.

12. The compound of claim 1 , wherein Z is

13. The compound of claim 12 , wherein Ar 2 is selected from the group consisting of 3,4-(methylenedioxy)phenyl and phenyl wherein the phenyl is substituted with 0, 1, or 2 substituents selected from the group consisting of alkoxy, alkoxycarbonyl, alkyl, alkylcarbonyl, carboxy, cyano, halogen, haloalkoxy, haloalkyl, hydroxy, nitro, —NR A R B , (NR A R B )alkyl, (NR A R B )alkoxy, and phenyl.

14. A compound of the formula (I):

Z-Ar 1 —Ar 2   (I)

or a pharmaceutically acceptable salt, ester, or amide thereof, wherein:

Z is a diazabicyclic amine of the formula:

Ar 1 is

Ar 2 is selected from the group consisting of an unsubstituted or substituted 5-or 6-membered heteroaryl ring; unsubstituted or substituted bicyclic heteroaryl ring; 3,4-(methylenedioxy)phenyl; carbazolyl; tetrahydrocarbazolyl; naphthyl; and phenyl; wherein the carbazolyl; tetrahydrocarbazolyl; naphthyl; and phenyl is substituted with 0, 1, 2, or 3 substituents selected from the group consisting of alkenyl, alkoxy, alkoxyalkoxy, alkoxyalkyl, alkoxycarbonyl, alkoxysulfonyl, alkyl, alkylcarbonyl, arylcarbonyl, alkylcarbonyloxy, alkylsulfonyl, alkylthio, alkynyl, carboxy, cyano, formyl, haloalkoxy, haloalkyl, halogen, hydroxy, hydroxyalkyl, mercapto, nitro, —NR A R B , (NR A R B )carbonyl, (NR A R B )sulfonyl, and phenyl;

l, m, o and p are each independently selected from the group consisting of 0, 1, or 2, and n is 0, provided that the sum total of l, m, n, o, and p is 3, 4, or 5, and further provided that the sum of l and o is at least 1 and the sum of m and p is at least 1;

R 1 is selected from the group consisting of hydrogen, alkenyl, alkyl alkoxycarbonyl, arylalkyl, and heteroarylalkyl;

R 2 at each occurrence is independently selected from the group consisting of hydrogen, alkoxycarbonyl, and alkyl;

R 3 is selected from the group consisting of hydrogen, alkoxy, alkyl, cyano, and hydroxyl;

R A and R B are each independently selected from the group consisting of hydrogen, alkyl, alkylcarbonyl, alkylsulfonyl, arylcarbonyl, formyl and (NR C R D )sulfonyl; and

R C and R D are each independently selected from the group consisting of hydrogen and alkyl.

15. The compound of claim 1 , or a pharmaceutically acceptable salt thereof, selected from the group consisting of:

3-(6-phenyl-pyridazin-3-yl)-3,8-diaza-bicyclo[3.2.1]octane;

8-methyl-3-(6-phenyl-pyridazin-3-yl)-3,8-diaza-bicyclo[3.2.1]octane;

6-methyl-3-(6-phenyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.1]octane;

3-(6-phenyl-pyridazin-3-yl)-3,8-diaza-bicyclo[4.2.0]octane;

8-methyl-3-(6-phenyl-pyridazin-3-yl)-3,8-diaza-bicyclo[4.2.0]octane;

2-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-methyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-(6-m-tolyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-methyl-5-(6-m-tolyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-[6-(4-methoxy-phenyl)-pyridazin-3-yl]-octahydro-pyrrolo[3,4-c]pyrrole;

diethyl-(2-{3-[6-(hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenoxy}-ethyl)-amine;

diethyl-(2-{3-[6-(5-methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenoxy}-ethyl)-amine;

(1S, 5S) 3-(6-phenyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.0]heptane;

(1S, 5S)-6-methyl-3-(6-phenyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.0]heptane;

(1R, 5S)-6-(6-phenyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.0]heptane;

(1R, 5S)-3-methyl-6-(6-phenyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.0]heptane;

(1R, 5R) 3-(6-phenyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.0]heptane;

(1R, 5R)-6-methyl-3-(6-phenyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.0]heptane;

(1R, 5R)-3-(6-benzo[1,3]dioxol-5-yl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.0]heptane;

(1R, 5R)-3-(6-benzo[1,3]dioxol-5-yl-pyridazin-3-yl)-6-methyl-3,6-diaza-bicyclo[3.2.0]heptane;

3-(6-Phenyl-pyridazin-3-yl)-3,8-diaza-bicyclo[4.2.0]octane;

8-(6-Phenyl-pyridazin-3-yl)-3,8-diaza-bicyclo[4.2.0]octane;

6a-Methyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-b]pyrrole;

2-(6-Phenyl-pyridazin-3-yl)-hexahydro-pyrrolo[3,4-c]pyrrole-3a-carboxylic acid ethyl ester;

2,5-Bis-(6-phenyl-pyridazin-3-yl)-hexahydro-pyrrolo[3,4-c]pyrrole-3a-carboxylic acid ethyl ester;

(1R, 5R)-6-(6-Phenyl-pyridazin-3-yl)-2,6-diaza-bicyclo[3.2.0]heptane;

(1R, 5R)-2-(6-Phenyl-pyridazin-3-yl)-2,6-diaza-bicyclo[3.2.0]heptane;

Ethyl 2-Methyl-5-(6-phenyl-pyridazin-3-yl)-hexahydro-pyrrolo[3,4-c]pyrrole-3a-carboxylate;

5-Methyl-2-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyridine;

1-Benzyl-6a-methyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-b]pyrrole;

3-Methyl-6-(6-phenyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.1]octane;

8-(6-Phenyl-pyridazin-3-yl)-3,8-diaza-bicyclo[4.2.0]octane;

3-Methyl-8-(6-phenyl-pyridazin-3-yl)-3,8-diaza-bicyclo[4.2.0]octane;

3-Methyl-8-(6-phenyl-pyridazin-3-yl)-3,8-diaza-bicyclo[3.2.1]octane;

1,6a-Dimethyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-b]pyrrole;

2-[6-(4-Bromo-phenyl)-pyridazin-3-yl]-5-methyl-octahydro-pyrrolo[3,4-c]pyrrole;

(1S, 5S)-3-[6-(4-Bromo-phenyl)-pyridazin-3-yl]-3,6-diaza-bicyclo[3.2.0]heptane;

(1S, 5S)-3-[6-(4-Bromo-phenyl)-pyridazin-3-yl]-6-methyl-3,6-diaza-bicyclo[3.2.0]heptane;

3-[6-(Hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-1H-indole;

3-[6-(5-Methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-1H-indole;

(1R, 5R)-3-[6-(3,6-Diaza-bicyclo[3.2.0]hept-3-yl)-pyridazin-3-yl]-1H-indole;

(1S, 5S)-3-[6-(3,6-Diaza-bicyclo[3.2.0]hept-3-yl)-pyridazin-3-yl]-1H-indole;

(1R, 5R)-3-[6-(6-Methyl-3,6-diaza-bicyclo[3.2.0]hept-3-yl)-pyridazin-3-yl]-1H-indole;

2-[6-(4-Nitro-phenyl)-pyridazin-3-yl]-octahydro-pyrrolo[3,4-c]pyrrole;

2-[6-(2-Nitro-phenyl)-pyridazin-3-yl]-octahydro-pyrrolo[3,4-c]pyrrole;

2-[6-(3-Nitro-phenyl)-pyridazin-3-yl]-octahydro-pyrrolo[3,4-c]pyrrole;

2-Methyl-5-[6-(4-nitro-phenyl)-pyridazin-3-yl]-octahydro-pyrrolo[3,4-c]pyrrole;

2-Methyl-5-[6-(3-nitro-phenyl)-pyridazin-3-yl]-octahydro-pyrrolo[3,4-c]pyrrole;

2-(6-Imidazol-1-yl-pyridazin-3-yl)-5-methyl-octahydro-pyrrolo[3,4-c]pyrrole;

2-(6-Imidazol-1-yl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

(1R, 5S)-6-[6-(4-Iodo-phenyl)-pyridazin-3-yl]-3,6-diaza-bicyclo[3.2.0]heptane;

(1S, 5S)-3-[6-(4-Iodo-phenyl)-pyridazin-3-yl]-3,6-diaza-bicyclo[3.2.0]heptane;

(1S, 5S)-3-[6-(4-Iodo-phenyl)-pyridazin-3-yl]-6-methyl-3,6-diaza-bicyclo[3.2.0]heptane;

2-(5-Methyl-6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-Methyl-5-(5-methyl-6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-(4-Methyl-6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-Methyl-5-(4-methyl-6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-(6-o-Tolyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-(6-p-Tolyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-[6-(3,5-Dimethyl-phenyl)-pyridazin-3-yl]-octahydro-pyrrolo[3,4-c]pyrrole;

2-(6-Furan-3-yl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-(6-Thiophen-3-yl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-Methyl-5-(6-thiophen-3-yl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

5-[6-(Hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-1H-indole;

5-[6-(Hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-1-methyl-1H-indole;

2-Methyl-5-(6-o-tolyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-Methyl-5-(6-p-tolyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-[6-(3,5-Dimethyl-phenyl)-pyridazin-3-yl]-5-methyl-octahydro-pyrrolo[3,4-c]pyrrole;

2-(6-Furan-3-yl-pyridazin-3-yl)-5-methyl-octahydro-pyrrolo[3,4-c]pyrrole;

5-[6-(5-Methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-1H-indole;

3-Methyl-5-[6-(5-methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-1H-indole;

2-Methyl-5-[6-(5-methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenylamine;

4-[6-(5-Methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenylamine;

4-[6-(5-Methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-1H-indole;

2-(6-Benzofuran-2-yl-pyridazin-3-yl)-5-methyl-octahydro-pyrrolo[3,4-c]pyrrole;

5-[6-(5-Methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-pyridin-2-ylamine;

2-Methyl-5-[6-(1H-pyrrol-3-yl)-pyridazin-3-yl]-octahydro-pyrrolo[3,4-c]pyrrole;

2-Methyl-5-(6-thiophen-2-yl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-Methyl-5-[6-(1H-pyrazol-4-yl)-pyridazin-3-yl]-octahydro-pyrrolo[3,4-c]pyrrole;

3-[6-(5-Methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-9H-carbazole;

2-(6-Furan-2-yl-pyridazin-3-yl)-5-methyl-octahydro-pyrrolo[3,4-c]pyrrole;

(1R, 5R)-3-(6-p-Tolyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.0]heptane;

(1R, 5R)-3-(6-o-Tolyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.]heptane;

(1R, 5R)-3-(6-m-Tolyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.0]heptane;

(1R, 5R)-6-Methyl-3-(6-p-tolyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.0]heptane;

(1R, 5R)-6-Methyl-3-(6-o-tolyl-pyridazin-3-yl)-3,6-diaza-bicyclo[3.2.0]heptane;

(1S, 5S)-5-[6-(3,6-Diaza-bicyclo[3.2.0]hept-3-yl)-pyridazin-3-yl]-1H-indole;

(1S, 5S)-5-[6-(6-Methyl-3,6-diaza-bicyclo[3.2.0]hept-3-yl)-pyridazin-3-yl]-1H-indole;

(1S, 5S)-4-[6-(6-Methyl-3,6-diaza-bicyclo[3.2.0]hept-3-yl)-pyridazin-3-yl]-1H-indole;

(1S, 5S)-3-(6-Benzofuran-5-yl-pyridazin-3-yl)-6-methyl-3,6-diaza-bicyclo[3.2.0]heptane;

(1S, 5S)-4-[6-(3,6-Diaza-bicyclo[3.2.0]hept-3-yl)-pyridazin-3-yl]-phenylamine;

(1R, 5S)-3-[6-(3-Methyl-3,6-diaza-bicyclo[3.2.0]hept-6-yl)-pyridazin-3-yl]-thiophene;

(1R, 5S)-5-[6-(3-Methyl-3,6-diaza-bicyclo[3.2.0]hept-6-yl)-pyridazin-3-yl]-1H-indole

(1R, 5S)-4-[6-(3-Methyl-3,6-diaza-bicyclo[3.2.0]hept-6-yl)-pyridazin-3-yl]-1H-indole

3-Methyl-5-[6-(5-methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-1H-indazole;

2-Benzyl-5-(6-phenylpyridazin-3-yl)-octahydropyrrolo[3,4-c]pyrrole;

2-(6-Phenylpyridazin-3-yl)-5-(pyridin-4-ylmethyl)-octahydropyrrolo[3,4-c]pyrrole;

2-(6-Phenylpyridazin-3-yl)-5-(pyridin-2-ylmethyl)-octahydropyrrolo[3,4-c]pyrrole;

2-(6-Chloropyridin-3-ylmethyl)-5-(6-phenylpyridazin-3-yl)-octahydropyrrolo[3,4-c]pyrrole;

2-(6-Phenylpyridazin-3-yl)-5-(2-pyridin-3-ylethyl)-octahydropyrrolo[3,4-c]pyrrole;

2-(6-Phenylpyridazin-3-yl)-5-(pyridin-3-ylmethyl)-octahydropyrrolo[3,4-c]pyrrole;

2-Allyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-But-2-enyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-Ethyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

2-(6-Phenyl-pyridazin-3-yl)-5-propyl-octahydro-pyrrolo[3,4-c]pyrrole;

2-Isopropyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole;

Diethyl-(2-{3-[6-(hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenoxy}-ethyl)-amine;

4-[6-(Hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenol;

Diethyl-(2-{4-[6-(hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenoxy}-ethyl)-amine;

(2-{4-[6-(Hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenoxy}-ethyl)-dimethyl-amine;

3-[6-(5-Methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenol;

4-[6-(5-Methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenol;

Diethyl-(2-{4-[6-(5-methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenoxy}-ethyl)-amine;

N-{4-[6-(5-Methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenyl}-methanesulfonamide;

N-{4-[6-(Hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenyl}-benzamide;

N-{4-[6-(Hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenyl}-methanesulfonamide;

N-{4-[6-(Hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenyl}-dimethylaminosulfonamide;

N-{4-[6-(Hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenyl}-acetamide;

N-{4-[6-(5-Methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-phenyl}-acetamide;

1-Methyl-5-[6-(5-methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-1H-indole;

Dimethyl-{5-[6-(5-methyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-pyridazin-3-yl]-1H-indol-3-ylmethyl}-amine; and

(1S, 5S)-6-[6-(6-Methyl-3,6-diaza-bicyclo[3.2.0]hept-3-yl)-pyridazin-3-yl]-2,3,4,9-tetrahydro-1H-carbazole.

16. A pharmaceutical composition comprising a therapeutically effective amount of a compound of claim 1 in combination with a pharmaceutically acceptable carrier.