Substituted naphthyridinone derivatives

1. A compound of structural formula I:

and pharmaceutically acceptable salts thereof, wherein:

R 1 is selected from:

(1) hydrogen,

(2) halogen,

(3) C 1-4 alkyl,

(4) —CN,

(5) —C(O)R 7 ,

(6) —OR d ,

(7) —NR 5 R 6 , and

(8) pyrrolidinyl,

wherein: alkyl moieties are unsubstituted or substituted with one substituent independently selected from R a ;

R 2 is selected from: —NR 5 R 6 , and C 1-6 alkyl;

R 3 is hydrogen;

R 4 is selected from:

(1) hydrogen, and

(2) —CH 2 —R 8 ;

R 5 is selected from:

(1) hydrogen,

(2) C 1-6 alkyl,

(3) trifluoromethyl, and

(4) methylcarbonyl,

R 6 is each selected from:

(1) hydrogen,

(2) C 1-6 alkyl,

(3) phenyl,

(4) benzyl,

(5) trifluoromethyl,

(6) —C(O)—R c ,

(7) —CO 2 R c , and

(8) —S(O) 2 CH 3 ,

or R 5 and R 6 together form ═CH—N(CH 3 ) 2 ;

R 7 is selected from:

(1) hydrogen,

(2) C 1-3 alkyl,

(3) —OR e , and

(4) —NR d R e ,

wherein the alkyl moieties are unsubstituted or substituted with one, two, or three substituents independently selected from R a ;

R 8 is selected from:

(1) hydrogen,

(2) —(CH 2 ) n OC(O)CH 3 ,

(3) C 1-6 alkyl,

(4) C 3-6 cycloalkyl,

(5) tetrahydrofuranyl,

(6) phenyl, and

(7) pyridyl;

wherein the alkyl moieties are unsubstituted or substituted with one substituent independently selected from —OR e , and the tetrahydrofuranyl, phenyl, and pyridyl moieties are unsubstituted or substituted with one, or two substituents independently selected from OR e , halogen, —NR e R f , —COCH 3 , —C(O)OCH 3 , —CN, and C 1-3 alkyl;

Ar 1 and Ar 2 are each phenyl, unsubstituted or substituted with one or two substituents independently selected from R b ;

each R a is independently selected from: —OR e , halogen, —NR e R f , —C(O)R c , —CO 2 R c , —OC(O)R c , —CN, CF 3 , and —OCF 3 ;

each R b is independently selected from:

(1) R a , and

(2) C 1-10 alkyl;

each R c is independently selected from: hydrogen, C 1-6 alkyl, and —NR d R d ; wherein each alkyl moiety may be substituted with one or two substituents selected from R h and oxo;

each R d is independently selected from hydrogen, and C 1-6 alkyl;

R e and R f are is independently selected from hydrogen and C 1-3 alkyl;

each R h is independently selected from:

(1) halogen,

(2) C 1-10 alkyl,

(3) —OR i ,

(4) —NR i R i , and

(5) —OC(O)R i ,

each R i is independently selected from:

(1) hydrogen,

(2) C 1-3 alkyl,

(3) trifluoromethyl, and

(4) cyclopropyl;

wherein each alkyl and cycloalkyl moiety is unsubstituted or substituted with one substituent selected from oxo, hydroxy, methoxy, acetoxy, halogen, cyano, and trifluoromethyl;

and

n is 1;

or a pharmaceutically acceptable salt thereof.

2. The compound according to claim 1 , wherein;

each R a is independently selected from: hydroxy, methoxy-, halogen, methylcarbonyl-, —CO 2 R c , —OC(O)R c , —CN, CF 3 , and —OCF 3 ;

each R d is independently selected from hydrogen, methyl, and ethyl;

each R h is independently selected from:

(1) halogen;

(2) C 1-3 alkyl;

(3) hydroxy;

(4) methoxy-; and

(5) —NR i R i ,

wherein R i is selected from hydrogen and methyl; methylcarbonyloxy- ; —CF 3 ; and —OCF 3 ;

or a pharmaceutically acceptable salt thereof.

3. The compound according to claim 2 , wherein

R 1 is selected from:

(1) halogen;

(2) C 1-3 alkyl, unsubstituted or substituted with hydroxy or methoxy;

(3) —CN;

(4) methyloxycarbonyl-;

(5) methylcarbonyl-;

(6) isopropyloxycarbonyl-;

(7) bromomethylcarbonyl-;

(8) —C(O)NH 2 ;

(9) methoxy-; and

(10) —NR 5 R 6 , wherein R 5 is methyl and R 6 is C 1-3 alkyl;

each R i is independently selected from: hydrogen, and methyl;

and pharmaceutically acceptable salts thereof.

4. The compound according to claim 2 , wherein

R 5 is selected from: hydrogen, methyl, and methlcarbonyl-, and

R 6 is hydrogen, C 1-3 alkyl, methyl benzyl, —C(═O)R c , or —SO 2 CH 3 ;

R 7 is selected from:

(1) C 1-3 alkyl, unsubstituted or substituted with halogen;

(2) —OR e ; and

(3) —NR d R e ;

wherein R d is selected from hydrogen and methyl, and R e is selected from hydrogen and C 1-3 alkyl;

and pharmaceutically acceptable salts thereof.

5. The compound according to claim 4 , wherein:

R 1 is selected from:

(1) —C(O)CH 3 ,

(2) —CH(OH)CH 3 ,

(3) —CH 3 ,

(4) —CH 2 CH 3 ,

(5) —CH(CH 3 ) 2 ,

(6) —CH(OCH 3 )(CH 3 ),

(7) —C(O)—OCH 3 ,

(8) —C(O)OCH(CH 3 ) 2 ,

(9) —CN, —C(O)NH 2 ,

(10) —C(O)N(CH 3 ) 2 ,—

(11) Cl

(12) —N(CH 3 ) 2 ,

(13) —N(CH 3 )(CH(CH 3 ) 2 ), and

(14) pyrrolidinyl;

R 2 is or C 1-6 alkyl or NR 5 R 6 , wherein R 5 is selected from: hydrogen, methyl, and methylcarbonyl-, and R 6 is selected from, hydrogen, methyl benzyl, —C(═O)R c , and —SO 2 CH 3 ;

R 5 is selected from: hydrogen, methyl, and methlcarbonyl-, and

R 6 is hydrogen, C 1-3 alkyl, methyl benzyl, or —C(═O)R c ;

Ar 1 is phenyl, substituted with one or two substituents independently selected from halogen and methyl;

Ar 2 is phenyl, either unsubstituted or substituted with one or two halogen substituents;

or a pharmaceutically acceptable salt thereof.

6. The compound according to claim 1 , of structural formula IA:

wherein R 1 , R 2 , and R 4 are as defined in claim 1 ;

and pharmaceutically acceptable salts thereof.

7. A compound selected from:

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

3-acetyl-4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-1,8-naphthyridin-2(1H)-one;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-(1-hydroxyethyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-1,8-naphthyridin-2(1H)-one;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-ethyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

3-acetyl-4-(benzylamino)-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-1,8-naphthyridin-2(1H)-one;

3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-4-(dimethylamino)-1-methyl-1,8-naphthyridin-2(1H)-one;

N′-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-N,N-dimethylurea;

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-N-methylacetamide;

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-2-methoxyacetamide;

N-[3-acetyl-1-benzyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[3-acetyl-6-(4-chlorophenyl)-1-(cyclopropylmethyl)-7-(2,4-dichlorophenyl)-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[3-acetyl-1-butyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-(2-methoxyethyl)-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-2-oxo-1-(tetrahydrofuran-2-ylmethyl)-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

2-{[3-acetyl-4-(acetylamino)-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-2-oxo-1,8-naphthyridin-1(2H)-yl]methyl}pyridinium trifluoroacetate;

3-{[3-acetyl-4-(acetylamino)-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-2-oxo-1,8-naphthyridin-1(2H)-yl]methyl}pyridinium trifluoroacetate;

2-[3-acetyl-4-(acetylamino)-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-2-oxo-1,8-naphthyridin-1(2H)-yl]ethyl acetate;

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-(2,4-dimethoxybenzyl)-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

4-{[3-acetyl-4-(acetylamino)-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-2-oxo-1,8-naphthyridin-1(2H)-yl]methyl}pyridinium trifluoroacetate;

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-2-oxo-1-propyl-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[3-acetyl-7-(2-chlorophenyl)-6-(4-chlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[3-acetyl-7-(2-chlorophenyl)-6-(4-chlorophenyl)-1-isobutyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-(1-(2,4-dimethoxybenzyl)-3-acetyl-7-(2,4-dichlorophenyl)-6-(4-chlorophenyl)-1,2-dihydro-2-oxo-1,8-naphthyridin-4-yl)-N-acetylacetamide;

N-(1-(2,4-dimethoxybenzyl)-7-(2,4-dichlorophenyl)-6-(4-chlorophenyl)-1,2-dihydro-2-oxo-1,8-naphthyridin-4-yl)-N-acetylacetamide;

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-(2-hydroxyethyl)-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]methanesulfonamide;

2-{[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]amino}-2-oxoethyl acetate;

N-[3-acetyl-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-2-hydroxyacetamide;

N-[3-acetyl-7-(2,4-dichlorophenyl)-1-methyl-6-(4-methylphenyl)-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[3-acetyl-7-(4-chlorophenyl)-6-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1,3-dimethyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]propanamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-ethyl-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]butanamide;

4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1,3-dimethyl-1,8-naphthyridin-2(1H)-one;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1,3-dimethyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methyl-1,8-naphthyridin-2(1H)-one;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-N-methylacetamide;

2-{[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]amino}-2-oxoethyl acetate;

2-chloro-N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-2-methoxyacetamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-N′-ethylurea;

N-[3-chloro-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-2-hydroxyacetamide;

N 1 -[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-N 2 ,N 2 -dimethylglycinamide;

N 1 -[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-N 2 -methylglycinamide;

N 1 -[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]glycinamide;

4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-ethyl-1-methyl-1,8-naphthyridin-2(1H)-one;

4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-isopropyl-1-methyl-1,8-naphthyridin-2(1H)-one;

4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-methyl-1-propyl-1,8-naphthyridin-2(1H)-one;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-ethyl-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-isopropyl-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-methyl-2-oxo-1-propyl-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-ethyl-1-isobutyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-(1-methoxyethyl)-1-methyl-1,8-naphthyridin-2(1H)-one;

4-amino-3-chloro-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-1,8-naphthyridin-2(1H)-one;

N-[3-chloro-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

4-amino-3-chloro-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-1,8-naphthyridin-2(1H)-one;

N-acetyl-N-(3-chloro-7-(2,4-dichlorophenyl)-6-(4-chlorophenyl)-1,2-dihydro-1-isobutyl-2-oxo-1,8-naphthyridin-4-yl)acetamide;

N-[3-chloro-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N 1 -[3-chloro-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-N 2 ,N 2 -dimethylglycinamide;

2-{[3-chloro-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]amino}-2-oxoethyl acetate;

N-[3-chloro-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-2-hydroxyacetamide;

N-acetyl-N-(3-chloro-7-(2-chlorophenyl)-6-(4-chlorophenyl)-1,2-dihydro-1-isobutyl-2-oxo-1,8-naphthyridin-4-yl)acetamide;

N-[3-chloro-7-(2-chlorophenyl)-6-(4-chlorophenyl)-1-isobutyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[3-chloro-7-(2-chloro-4-fluorophenyl)-6-(4-chlorophenyl)-1-isobutyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-(dimethylamino)-1-methyl-1,8-naphthyridin-2(1H)-one;

N-acetyl-N-(7-(2,4-dichlorophenyl)-6-(4-chlorophenyl)-3-(dimethylamino)-1,2-dihydro-1-methyl-2-oxo-1,8-naphthyridin-4-yl)acetamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-(dimethylamino)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-[isopropyl(methyl)amino]-1-methyl-1,8-naphthyridin-2(1H)-one;

N-(3-(N-isopropyl-N-methylamino)-7-(2,4-dichlorophenyl)-6-(4-chlorophenyl)-1,2-dihydro-1-methyl-2-oxo-1,8-naphthyridin-4-yl)-N-acetylacetamide;

N-{6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-[isopropyl(methyl)amino]-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl}acetamide;

N-acetyl-N-(7-(2,4-dichlorophenyl)-6-(4-chlorophenyl)-1,2-dihydro-1-methyl-2-oxo-3-(pyrrolidin-1-yl)-1,8-naphthyridin-4-yl)acetamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-3-pyrrolidin-1-yl-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-methoxy-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N-acetyl-N-(7-(2,4-dichlorophenyl)-6-(4-chlorophenyl)-1,2-dihydro-1-isobutyl-3-methoxy-2-oxo-1,8-naphthyridin-4-yl)acetamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methoxy-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

N′-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-N,N-dimethylimidoformamide;

N′-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-ethyl-1-isobutyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-N,N-dimethylimidoformamide;

N′-[3-chloro-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-N,N-dimethylimidoformamide;

N′-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-isobutyl-3-methoxy-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]-N,N-dimethylimidoformamide;

N-[6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-(1-methoxyethyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-3-isopropyl-1-methyl-4-(methylamino)-1,8-naphthyridin-2(1H)-one;

methyl 4-(acetylamino)-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxylate;

methyl 4-(N-acetylacetamido)-7-(2,4-dichlorophenyl)-6-(4-chlorophenyl)-1,2-dihydro-1-methyl-2-oxo-1,8-naphthyridine-3-carboxylate;

isopropyl 4-(acetylamino)-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxylate;

ethyl 4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxylate;

4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide;

4-(acetylamino)-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-N,N,1-trimethyl-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide;

4-amino-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carbonitrile;

N-[6-(4-chlorophenyl)-3-cyano-7-(2,4-dichlorophenyl)-1-methyl-2-oxo-1,2-dihydro-1,8-naphthyridin-4-yl]acetamide;

and pharmaceutically acceptable salts thereof.

8. A composition comprising a compound according to claim 1 and a pharmaceutically acceptable carrier.