Naphthyridinedione derivatives

Abstract

or a salt thereof, wherein the substituents are as defined in the specification; to its preparation, to its use as medicament and to medicaments comprising it.

1 .- 9 . (canceled) 
     
     
         10 . A method of suppressing the effect of nonsense mutations in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of the compound of Formula (Ia′) or a pharmaceutically acceptable salt thereof, wherein: 
       
         
           
           
               
               
           
         
         R 1  is selected from a five- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur, and wherein said ring system may be substituted once or more than once by R 6 ; pyrrolyl; pyrazolyl; thiophenyl; and pyridin-2-yl; and 
       
       
         
           
           
               
               
           
         
       
       wherein the phenyl ring is attached via the bond marked with an asterisk (*), and wherein the pyrrolyl, pyrazolyl, thiophenyl, and pyridin-2-yl may be substituted by C 1-3 alkyl;
 wherein when R 1  is a five- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, then R 2  is selected from C 2-6 alkyl which may be substituted once or more than once by R 7 ; —X 1 —R 8 ; and a three- to seven-membered monocyclic aromatic, saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur, and wherein said ring system may be substituted once or more than once by R 11 ; 
 or wherein when R 1  is pyrrolyl, pyrazolyl, thiophenyl, pyridin-2-yl, or phenyl, then R 2  is selected from C 2-7 alkyl which may be substituted once or more than once by R 13 ; —X 2 —R 14 ; and a three- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur, and wherein said ring system may be substituted once or more than once by R 17 ; 
 X 1 — is —O—, —S— or —N(R 9 )—; 
 X 2 — is —O—, —S— or —N(R 15 )—; 
 R 3  is hydrogen or —CH 2 R 18 ; 
 R 8  is C 1-6 alkyl which may be substituted once or more than once by R 10 ; 
 R 9  is hydrogen or C 1-4 alkyl; 
 each R 12  independently is hydrogen, halogen, hydroxyl, amino, cyano, nitro, C 1-4 alkyl, C 1-4 halogenalkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy-C 1-4 alkyl, amino-C 1-4 alkyl, C 1-4 alkyl-amino-C 1-4 alkyl, di(C 1-4 alkyl)-amino-C 1-4 alkyl, C 1-4 alkoxy, C 1-4 halogenalkoxy, C 1-4 alkylamino or di(C 1-4 alkyl)amino; or C 3-6 cycloalkyl, wherein one carbon atom may be replaced by an oxygen atom, wherein the C 3-6 cycloalkyl may be attached directly or via a C 1-2 alkylene, and wherein the C 3-6 cycloalkyl may be substituted once or more than once by halogen; 
 R 14  is C 1-6 alkyl which may be substituted once or more than once by R 16 ; 
 R 15  is hydrogen or C 1-4 alkyl; 
 R 18  is hydrogen, C 1-4 alkyl, C 2-6 alkenyl, C 3-6 cycloalkyl, C 1-3 alkoxyC 1-3 alkyl, hydroxyC 1-3 alkyl, or aminoC 1-3 alkyl; 
 R 21  is hydrogen, halogen, hydroxyl, amino, cyano, C 1-4 alkyl, C 1-4 halogenalkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy-C 1-4 alkyl, amino-C 1-4 alkyl, C 1-4 alkyl-amino-C 1-4 alkyl, di(C 1-4 alkyl)-amino-C 1-4 alkyl, C 1-4 alkoxy, C 1-4 halogenalkoxy, C 1-4 alkylamino, di(C 1-4 alkyl)amino; or a three- to seven-membered monocyclic aromatic, saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, wherein said ring system may be attached directly or via a C 1-2 alkylene, and wherein said ring system may be substituted once or more than once by R 23 ; 
 R 22  is hydrogen, halogen, hydroxyl, cyano, C 1-4 alkyl, C 1-4 halogenalkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy-C 1-4 alkyl, amino-C 1-4 alkyl, C 1-4 alkyl-amino-C 1-4 alkyl, di(C 1-4 alkyl)-amino-C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkinyl, C 1-4 alkoxy, C 1-4 halogenalkoxy, or C 3-4 cycloalkyl, wherein one carbon atom of the C 3-4 cycloalkyl may be replaced by an oxygen atom, wherein the C 3-4 cycloalkyl may be attached directly or via a C 1-2 alkylene, and wherein the C 3-4 cycloalkyl may be substituted once or more than once by halogen; 
 R 6 , R 11 , R 17 , and R 23  each independently is halogen, hydroxyl, amino, cyano, nitro, C 1-4 alkyl, C 1-4 halogenalkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy-C 1-4 alkyl, amino-C 1-4 alkyl, C 1-4 alkyl-amino-C 1-4 alkyl, di(C 1-4 alkyl)-amino-C 1-4 alkyl, C 1-4 alkoxy, C 1-4 halogenalkoxy, C 1-4 alkylamino, di(C 1-4 alkyl)amino, or C 3-6 cycloalkyl, wherein one carbon atom of the C 3-6 cycloalkyl may be replaced by an oxygen atom, wherein the C 3-6 cycloalkyl may be attached directly or via a C 1-2 alkylene, and wherein the C 3-6 cycloalkyl may be substituted once or more than once by halogen; 
 or two R 6 , R 11 , R 17 , and R 23  at the same ring atom together are oxo; 
 or two R 6 , R 11 , R 17 , and R 23  at the same ring carbon atom together with said carbon atom form a C 3-6 cycloalkyl; 
 R 7 , R 10 , R 13 , and R 16  each independently is halogen, hydroxyl, amino, cyano, nitro, C 1-4 alkoxy, C 1-4 halogenalkoxy, C 1-4 alkylamino, di(C 1-4 alkyl)amino, or C 3-6 cycloalkyl, wherein one carbon atom of the C 3-6 cycloalkyl may be replaced by an oxygen atom, wherein the C 3-6 cycloalkyl may be attached directly or via a C 1-2 alkylene, and wherein the C 3-6 cycloalkyl may be substituted once or more than once by halogen; 
 or two R 7 , R 10 , R 13 , or R 16  at the same carbon atom together are oxo; 
 or two R 7 , R 10 , R 13 , or R 16  at the same carbon atom together with said carbon atom form a C 3-6 cycloalkyl; and 
 R 24  is hydrogen or halogen. 
 
     
     
         11 . A method of treating a disease caused by nonsense mutations in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a compound of Formula (Ia′) or a pharmaceutically acceptable salt thereof, wherein: 
       
         
           
           
               
               
           
         
         R 1  is selected from a five- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 6 ; pyrrolyl; pyrazolyl; thiophenyl; and pyridin-2-yl; and 
       
       
         
           
           
               
               
           
         
       
       wherein the phenyl ring is attached via the bond marked with an asterisk (*), and wherein the pyrrolyl, pyrazolyl, thiophenyl, and pyridin-2-yl may be substituted by C 1-3 alkyl;
 wherein when R 1  is a five- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, then R 2  is selected from C 2-6 alkyl which may be substituted once or more than once by R 7 ; —X 1 -RE 8  and a three- to seven-membered monocyclic aromatic, saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur, and wherein said ring system may be substituted once or more than once by R 11 ; 
 or wherein when R 1  is pyrrolyl, pyrazolyl, thiophenyl, pyridin-2-yl, or phenyl, then R 2  is selected from C 2-7 alkyl which may be substituted once or more than once by R 13 ; —X 2 —R 14 ; and a three- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur, and wherein said ring system may be substituted once or more than once by R 17 ; 
 X 1 — is —O—, —S— or —N(R 9 )—; 
 X 2 — is —O—, —S— or —N(R 15 )—; 
 R 3  is hydrogen or —CH 2 R 18 ; 
 R 8  is C 1-6 alkyl which may be substituted once or more than once by R 10 ; 
 R 9  is hydrogen or C 1-4 alkyl; 
 each R 12  independently is hydrogen, halogen, hydroxyl, amino, cyano, nitro, C 1-4 alkyl, C 1-4 halogenalkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy-C 1-4 alkyl, amino-C 1-4 alkyl, C 1-4 alkyl-amino-C 1-4 alkyl, di(C 1-4 alkyl)-amino-C 1-4 alkyl, C 1-4 alkoxy, C 1-4 halogenalkoxy, C 1-4 alkylamino or di(C 1-4 alkyl)amino; or C 3-6 cycloalkyl, wherein one carbon atom may be replaced by an oxygen atom, wherein the C 3-6 cycloalkyl may be attached directly or via a C 1-2 alkylene, and wherein the C 3-6 cycloalkyl may be substituted once or more than once by halogen; 
 R 14  is C 1-6 alkyl which may be substituted once or more than once by R 16 ; 
 R 15  is hydrogen or C 1-4 alkyl; 
 R 18  is hydrogen, C 1-4 alkyl, C 2-6 alkenyl, C 3-6 cycloalkyl, C 1-3 alkoxyC 1-3 alkyl, hydroxyC 1-3 alkyl, or aminoC 1-3 alkyl; 
 R 21  is hydrogen, halogen, hydroxyl, amino, cyano, C 1-4 alkyl, C 1-4 halogenalkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy-C 1-4 alkyl, amino-C 1-4 alkyl, C 1-4 alkyl-amino-C 1-4 alkyl, di(C 1-4 alkyl)-amino-C 1-4 alkyl, C 1-4 alkoxy, C 1-4 halogenalkoxy, C 1-4 alkylamino, di(C 1-4 alkyl)amino; or a three- to seven-membered monocyclic aromatic, saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, wherein said ring system may be attached directly or via a C 1-2 alkylene, and wherein said ring system may be substituted once or more than once by R 23 ; 
 R 22  is hydrogen, halogen, hydroxyl, cyano, C 1-4 alkyl, C 1-4 halogenalkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy-C 1-4 alkyl, amino-C 1-4 alkyl, C 1-4 alkyl-amino-C 1-4 alkyl, di(C 1-4 alkyl)-amino-C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkinyl, C 1-4 alkoxy, C 1-4 halogenalkoxy, or C 3-4 cycloalkyl, wherein one carbon atom of the C 3-4 cycloalkyl may be replaced by an oxygen atom, wherein the C 3-4 cycloalkyl may be attached directly or via a C 1-2 alkylene, and wherein the C 3-4 cycloalkyl may be substituted once or more than once by halogen; 
 R 6 , R 11 , R 17 , and R 23  each independently is halogen, hydroxyl, amino, cyano, nitro, C 1-4 alkyl, C 1-4 halogenalkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy-C 1-4 alkyl, amino-C 1-4 alkyl, C 1-4 alkyl-amino-C 1-4 alkyl, di(C 1-4 alkyl)-amino-C 1-4 alkyl, C 1-4 alkoxy, C 1-4 halogenalkoxy, C 1-4 alkylamino, di(C 1-4 alkyl)amino, or C 3-6 cycloalkyl, wherein one carbon atom of the C 3-6 cycloalkyl may be replaced by an oxygen atom, wherein the C 3-6 cycloalkyl may be attached directly or via a C 1-2 alkylene, and wherein the C 3-6 cycloalkyl may be substituted once or more than once by halogen; 
 or two R 6 , R 11 , R 17 , and R 23  at the same ring atom together are oxo; 
 or two R 6 , R 11 , R 17 , and R 23  at the same ring carbon atom together with said carbon atom form a C 3-6 cycloalkyl; 
 R 7 , R 10 , R 13 , and R 16  each independently is halogen, hydroxyl, amino, cyano, nitro, C 1-4 alkoxy, C 1-4 halogenalkoxy, C 1-4 alkylamino, di(C 1-4 alkyl)amino, or C 3-6 cycloalkyl, wherein one carbon atom of the C 3-6 cycloalkyl may be replaced by an oxygen atom, wherein the C 3-6 cycloalkyl may be attached directly or via a C 1-2 alkylene, and wherein the C 3-6 cycloalkyl may be substituted once or more than once by halogen; 
 or two R 7 , R 10 , R 13 , or R 16  at the same carbon atom together are oxo; 
 or two R 7 , R 10 , R 13 , or R 16  at the same carbon atom together with said carbon atom form a C 3-6 cycloalkyl; and 
 R 24  is hydrogen or halogen. 
 
     
     
         12 . The method of  claim 11 , wherein the disease is selected from hemophilia A, hemophilia B, cystic fibrosis, mucopolysaccharidosis I, Duchenne Muscle Dystrophy, Becker Muscle Dystrophy, loss of APC caused cancer and loss of p53 caused cancer. 
     
     
         13 . A method of treating Duchenne Muscle Dystrophy in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a compound of Formula (Ia′) or a pharmaceutically acceptable salt thereof, wherein: 
       
         
           
           
               
               
           
         
         R 1  is selected from a five- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 6 ; pyrrolyl; pyrazolyl; thiophenyl; and pyridin-2-yl; and 
       
       
         
           
           
               
               
           
         
       
       wherein the phenyl ring is attached via the bond marked with an asterisk (*), and wherein the pyrrolyl, pyrazolyl, thiophenyl, and pyridin-2-yl may be substituted by C 1-3 alkyl;
 wherein when R 1  is a five- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, then R 2  is selected from C 2-6 alkyl which may be substituted once or more than once by R 7 ; —X 1 —R 8 ; and a three- to seven-membered monocyclic aromatic, saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 11 ; 
 or wherein when R 1  is pyrrolyl, pyrazolyl, thiophenyl, pyridin-2-yl, or phenyl, then R 2  is selected from C 2-7 alkyl which may be substituted once or more than once by R 13 ; —X 2 —R 14 ; and a three- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 17 ; 
 X 1 — is —O—, —S— or —N(R 9 )—; 
 X 2 — is —O—, —S— or —N(R 15 )—; 
 R 3  is hydrogen or —CH 2 R 18 ; 
 R 8  is C 1-6 alkyl which may be substituted once or more than once by R 10 ; 
 R 9  is hydrogen or C 1-4 alkyl; 
 each R 12  independently is hydrogen, halogen, hydroxyl, amino, cyano, nitro, C 1-4 alkyl, C 1-4 halogenalkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy-C 1-4 alkyl, amino-C 1-4 alkyl, C 1-4 alkyl-amino-C 1-4 alkyl, di(C 1-4 alkyl)-amino-C 1-4 alkyl, C 1-4 alkoxy, C 1-4 halogenalkoxy, C 1-4 alkylamino, or di(C 1-4 alkyl)amino; or C 3-6 cycloalkyl, wherein one carbon atom may be replaced by an oxygen atom, wherein the C 3-6 cycloalkyl may be attached directly or via a C 1-2 alkylene, and wherein the C 3-6 cycloalkyl may be substituted once or more than once by halogen; 
 R 14  is C 1-6 alkyl which may be substituted once or more than once by R 16 ; 
 R 15  is hydrogen or C 1-4 alkyl; 
 R 18  is hydrogen, C 1-4 alkyl, C 2-6 alkenyl, C 3-6 cycloalkyl, C 1-3 alkoxyC 1-3 alkyl, hydroxyC 1-3 alkyl or aminoC 1-3 alkyl; 
 R 21  is hydrogen, halogen, hydroxyl, amino, cyano, C 1-4 alkyl, C 1-4 halogenalkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy-C 1-4 alkyl, amino-C 1-4 alkyl, C 1-4 alkyl-amino-C 1-4 alkyl, di(C 1-4 alkyl)-amino-C 1-4 alkyl, C 1-4 alkoxy, C 1-4 halogenalkoxy, C 1-4 alkylamino, di(C 1-4 alkyl)amino; or a three- to seven-membered monocyclic aromatic, saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, wherein said ring system may be attached directly or via a C 1-2 alkylene, and wherein said ring system may be substituted once or more than once by R 23 ; 
 R 22  is hydrogen, halogen, hydroxyl, cyano, C 1-4 alkyl, C 1-4 halogenalkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy-C 1-4 alkyl, amino-C 1-4 alkyl, C 1-4 alkyl-amino-C 1-4 alkyl, di(C 1-4 alkyl)-amino-C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkinyl, C 1-4 alkoxy, C 1-4 halogenalkoxy, or C 3-4 cycloalkyl, wherein one carbon atom of the C 3-4 cycloalkyl may be replaced by an oxygen atom, wherein the C 3-4 cycloalkyl may be attached directly or via a C 1-2 alkylene, and wherein the C 3-4 cycloalkyl may be substituted once or more than once by halogen; 
 R 6 , R 11 , R 17 , and R 23  each independently is halogen, hydroxyl, amino, cyano, nitro, C 1-4 alkyl, C 1-4 halogenalkyl, C 1-4 hydroxyalkyl, C 1-4 alkoxy-C 1-4 alkyl, amino-C 1-4 alkyl, C 1-4 alkyl-amino-C 1-4 alkyl, di(C 1-4 alkyl)-amino-C 1-4 alkyl, C 1-4 alkoxy, C 1-4 halogenalkoxy, C 1-4 alkylamino, di(C 1-4 alkyl)amino, or C 3-6 cycloalkyl, wherein one carbon atom of the C 3-6 cycloalkyl may be replaced by an oxygen atom, wherein the C 3-6 cycloalkyl may be attached directly or via a C 1-2 alkylene, and wherein the C 3-6 cycloalkyl may be substituted once or more than once by halogen; 
 or two R 6 , R 11 , R 17 , and R 23  at the same ring atom together are oxo; 
 or two R 6 , R 11 , R 17 , and R 23  at the same ring carbon atom together with said carbon atom form a C 3-6 cycloalkyl; 
 R 7 , R 10 , R 13 , and R 16  each independently is halogen, hydroxyl, amino, cyano, nitro, C 1-4 alkoxy, C 1-4 halogenalkoxy, C 1-4 alkylamino, di(C 1-4 alkyl)amino, or C 3-6 cycloalkyl, wherein one carbon atom of the C 3-6 cycloalkyl may be replaced by an oxygen atom, wherein the C 3-6 cycloalkyl may be attached directly or via a C 1-2 alkylene, and wherein the C 3-6 cycloalkyl may be substituted once or more than once by halogen; 
 or two R 7 , R 10 , R 13 , or R 16  at the same carbon atom together are oxo; 
 or two R 7 , R 10 , R 13 , or R 16  at the same carbon atom together with said carbon atom form a C 3-6 cycloalkyl; and 
 R 24  is hydrogen or halogen. 
 
     
     
         14 . The method of  claim 10 , wherein:
 R 1  is phenyl;   R 12  for each occurrence is hydrogen; and   R 2  is selected from C 2-7 alkyl which may be substituted once or more than once by R 13 ; and a three- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 17 .   
     
     
         15 . The method of  claim 10 , wherein:
 R 1  is a ring selected from pyrazolyl, thiophenyl, and pyridin-2-yl, which ring may be substituted by C 1-3 alkyl; and   R 2  is selected from C 2-7 alkyl which may be substituted once or more than once by R 13 ; and a three- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 17 .   
     
     
         16 . The method of  claim 10 , wherein:
 R 1  is a five- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 6 ; and   R 2  is selected from C 2-6 alkyl which may be substituted once or more than once by R 7  and a three- to seven-membered monocyclic aromatic, saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 11 .   
     
     
         17 . The method of  claim 10 , wherein the compound or a pharmaceutically acceptable salt thereof is selected from:
 3-cyclobutyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-fluoro-3-isopropyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-fluoro-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-chloro-3-isopropyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-chloro-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-8-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-5,8-dimethyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   9-isopropyl-8-phenyl-1H-indolo[1,7-ab][1,6]naphthyridine-6,7(2H, 8H)-dione;   7-isopropyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   7-isopropyl-9-methyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H, 9H)-dione;   7-isopropyl-2-methyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   7-isopropyl-2,9-dimethyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   6-isopropyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-isopropyl-4-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-isopropyl-2-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-isopropyl-2,4-dimethyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H, 7H)-dione;   6-isopropyl-3-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-isopropyl-3,4-dimethyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   3-isopropyl-2-phenyl-6,7,8,9-tetrahydrobenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-2-phenyl-5,6,7,8-tetrahydro-1H-cyclopenta[b][1,6]naphthyridine-1,9(2H)-dione;   3-cyclobutyl-5-methyl-2-phenyl-5,6,7,8-tetrahydro-1H-cyclopenta[b][1,6]naphthyridine-1,9(2H)-dione;   3-cyclobutyl-2-phenyl-5,6,7,8-tetrahydro-1H-cyclopenta[b][1,6]naphthyridine-1,9(2H)-dione;   3-cyclobutyl-5-methyl-2-phenyl-6,7,8,9-tetrahydrobenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   7-cyclobutyl-9-methyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   7-cyclobutyl-2,9-dimethyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   7-cyclobutyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H, 9H)-dione;   7-cyclobutyl-2-methyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   6-cyclobutyl-4-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-cyclobutyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H, 7H)-dione;   6-cyclobutyl-2,4-dimethyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-cyclobutyl-2-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   3-cyclobutyl-5,8-dimethyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-8-fluoro-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-chloro-3-cyclobutyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-8-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-chloro-3-cyclobutyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-6-methoxy-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-8-fluoro-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   9-cyclobutyl-8-phenyl-1H-indolo[1,7-ab][1,6]naphthyridine-6,7(2H,8H)-dione;   3-cyclobutyl-6-methoxy-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-6-methoxy-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-6-methoxy-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-8-methoxy-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-8-methoxy-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-hydroxy-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   6-hydroxy-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-2-cyclopentylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-2-cyclopentyl-5-methylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   2-cyclopentyl-3-isopropylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   2-cyclopentyl-3-isopropyl-5-methylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-2-(pyridin-2-yl)benzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-5-methyl-2-(pyridin-2-yl)benzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-2-(pyrrolidin-1-yl)benzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-5-methyl-2-(pyrrolidin-1-yl)benzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   4-chloro-3-isopropyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   4-chloro-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione; and   4-bromo-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione.   
     
     
         18 . The method of  claim 11 , wherein:
 R 1  is phenyl;   R 12  for each occurrence is hydrogen; and   R 2  is selected from C 2-7 alkyl which may be substituted once or more than once by R 13 ; and a three- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 17 .   
     
     
         19 . The method of  claim 11 , wherein:
 R 1  is a ring selected from pyrazolyl, thiophenyl and pyridin-2-yl, which ring may be substituted by C 1-3 alkyl; and   R 2  is selected from C 2-7 alkyl which may be substituted once or more than once by R 13 ; and a three- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 17 .   
     
     
         20 . The method of  claim 11 , wherein:
 R 1  is a five- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 hetero atoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 6 ; and   R 2  is selected from C 2-6 alkyl which may be substituted once or more than once by R 7  and a three- to seven-membered monocyclic aromatic, saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur, and wherein said ring system may be substituted once or more than once by R 11 .   
     
     
         21 . The method of  claim 11 , wherein the compound or a pharmaceutically acceptable salt thereof is selected from:
 3-cyclobutyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-fluoro-3-isopropyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-fluoro-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-chloro-3-isopropyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-chloro-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-8-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-5,8-dimethyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   9-isopropyl-8-phenyl-1H-indolo[1,7-ab][1,6]naphthyridine-6,7(2H, 8H)-dione;   7-isopropyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   7-isopropyl-9-methyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H, 9H)-dione;   7-isopropyl-2-methyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H, 9H)-dione;   7-isopropyl-2,9-dimethyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   6-isopropyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-isopropyl-4-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-isopropyl-2-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-isopropyl-2,4-dimethyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H, 7H)-dione;   6-isopropyl-3-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-isopropyl-3,4-dimethyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   3-isopropyl-2-phenyl-6,7,8,9-tetrahydrobenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-2-phenyl-5,6,7,8-tetrahydro-1H-cyclopenta[b][1,6]naphthyridine-1,9(2H)-dione;   3-cyclobutyl-5-methyl-2-phenyl-5,6,7,8-tetrahydro-1H-cyclopenta[b][1,6]naphthyridine-1,9(2H)-dione;   3-cyclobutyl-2-phenyl-5,6,7,8-tetrahydro-1H-cyclopenta[b][1,6]naphthyridine-1,9(2H)-dione;   3-cyclobutyl-5-methyl-2-phenyl-6,7,8,9-tetrahydrobenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   7-cyclobutyl-9-methyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   7-cyclobutyl-2,9-dimethyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   7-cyclobutyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H, 9H)-dione;   7-cyclobutyl-2-methyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   6-cyclobutyl-4-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-cyclobutyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H, 7H)-dione;   6-cyclobutyl-2,4-dimethyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-cyclobutyl-2-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   3-cyclobutyl-5,8-dimethyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-8-fluoro-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-chloro-3-cyclobutyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-8-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-chloro-3-cyclobutyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-6-methoxy-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-8-fluoro-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   9-cyclobutyl-8-phenyl-1H-indolo[1,7-ab][1,6]naphthyridine-6,7(2H,8H)-dione;   3-cyclobutyl-6-methoxy-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-6-methoxy-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-6-methoxy-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-8-methoxy-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-8-methoxy-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-hydroxy-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   6-hydroxy-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-2-cyclopentylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-2-cyclopentyl-5-methylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   2-cyclopentyl-3-isopropylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   2-cyclopentyl-3-isopropyl-5-methylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-2-(pyridin-2-yl)benzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-5-methyl-2-(pyridin-2-yl)benzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-2-(pyrrolidin-1-yl)benzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-5-methyl-2-(pyrrolidin-1-yl)benzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   4-chloro-3-isopropyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   4-chloro-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione; and   4-bromo-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione.   
     
     
         22 . The method of  claim 13 , wherein:
 R 1  is phenyl;   R 12  for each occurrence is hydrogen; and   R 2  is selected from C 2-7 alkyl which may be substituted once or more than once by R 13 ; and a three- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 17 .   
     
     
         23 . The method of  claim 13 , wherein:
 R 1  is a ring selected from pyrazolyl, thiophenyl and pyridin-2-yl, which ring may be substituted by C 1-3 alkyl; and   R 2  is selected from C 2-7 alkyl which may be substituted once or more than once by R 13 ; and a three- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 17 .   
     
     
         24 . The method of  claim 13 , wherein:
 R 1  is a five- to seven-membered monocyclic saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur, and wherein said ring system may be substituted once or more than once by R 6 ; and   R 2  is selected from C 2-6 alkyl which may be substituted once or more than once by R 7  and a three- to seven-membered monocyclic aromatic, saturated or unsaturated non-aromatic ring system, wherein said ring system may contain from 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur, and wherein said ring system may be substituted once or more than once by R 11 .   
     
     
         25 . The method of  claim 13 , wherein the compound or a pharmaceutically acceptable salt thereof is selected from:
 3-cyclobutyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-fluoro-3-isopropyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-fluoro-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-chloro-3-isopropyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-chloro-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-8-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-5,8-dimethyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   9-isopropyl-8-phenyl-1H-indolo[1,7-ab][1,6]naphthyridine-6,7(2H, 8H)-dione;   7-isopropyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   7-isopropyl-9-methyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H, 9H)-dione;   7-isopropyl-2-methyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H, 9H)-dione;   7-isopropyl-2,9-dimethyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   6-isopropyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-isopropyl-4-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-isopropyl-2-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-isopropyl-2,4-dimethyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H, 7H)-dione;   6-isopropyl-3-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-isopropyl-3,4-dimethyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   3-isopropyl-2-phenyl-6,7,8,9-tetrahydrobenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-2-phenyl-5,6,7,8-tetrahydro-1H-cyclopenta[b][1,6]naphthyridine-1,9(2H)-dione;   3-cyclobutyl-5-methyl-2-phenyl-5,6,7,8-tetrahydro-1H-cyclopenta[b][1,6]naphthyridine-1,9(2H)-dione;   3-cyclobutyl-2-phenyl-5,6,7,8-tetrahydro-1H-cyclopenta[b][1,6]naphthyridine-1,9(2H)-dione;   3-cyclobutyl-5-methyl-2-phenyl-6,7,8,9-tetrahydrobenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   7-cyclobutyl-9-methyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   7-cyclobutyl-2,9-dimethyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H, 9H)-dione;   7-cyclobutyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H, 9H)-dione;   7-cyclobutyl-2-methyl-6-phenylthieno[2,3-b][1,6]naphthyridine-4,5(6H,9H)-dione;   6-cyclobutyl-4-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-cyclobutyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H, 7H)-dione;   6-cyclobutyl-2,4-dimethyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   6-cyclobutyl-2-methyl-7-phenylthieno[3,2-b][1,6]naphthyridine-8,9(4H,7H)-dione;   3-cyclobutyl-5,8-dimethyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-8-fluoro-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-chloro-3-cyclobutyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-8-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-chloro-3-cyclobutyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-6-methoxy-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-8-fluoro-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   9-cyclobutyl-8-phenyl-1H-indolo[1,7-ab][1,6]naphthyridine-6,7(2H,8H)-dione;   3-cyclobutyl-6-methoxy-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-6-methoxy-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-6-methoxy-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-8-methoxy-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-isopropyl-8-methoxy-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   8-hydroxy-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   6-hydroxy-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-2-cyclopentylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-2-cyclopentyl-5-methylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   2-cyclopentyl-3-isopropylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   2-cyclopentyl-3-isopropyl-5-methylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-2-(pyridin-2-yl)benzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-5-methyl-2-(pyridin-2-yl)benzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-2-(pyrrolidin-1-yl)benzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   3-cyclobutyl-5-methyl-2-(pyrrolidin-1-yl)benzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   4-chloro-3-isopropyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione;   4-chloro-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione; and   4-bromo-3-isopropyl-5-methyl-2-phenylbenzo[b][1,6]naphthyridine-1,10(2H,5H)-dione.