Poly (ADP-ribose) polymerase inhibitor

1. A compound represented by Formula (II) or (III):

or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:

R is selected from the group consisting of hydrogen, chloro, fluoro, bromo, iodo, nitro, hydroxyl, amino, branched or straight-chain C 1 -C 6 alkyl, haloalkyl, CF 3 , CN, NR 11 R 12 , NH—CO—R 13 and O—C 1 -C 4 alkyl, wherein R 11 and R 12 are each independently hydrogen or C 1 -C 4 alkyl, R 13 is hydrogen, C 1 -C 4 alkyl, C 1 -C 4 alkyl-phenyl or benzyl;

X 1 , X 2 are each independently selected from —CH or —N, but they are not —N simultaneously;

and R′ is selected from the group consisting of —H, —C(O)R 1 , —C(O)NR 1 R 2 , —CO 2 R 1 , substituted or unsubstituted C 1-10 alkyl, substituted or unsubstituted C 2-10 alkenyl, substituted or unsubstituted C 3-10 cycloalkyl, substituted or unsubstituted C 5-10 cycloalkenyl, substituted or unsubstituted C 1-10 alkoxy, substituted or unsubstituted C 2-10 alkenyloxy, substituted or unsubstituted 3-10-membered saturated or unsaturated monocyclic heterocyclic ring comprising 1-3 heteroatoms selected from N, O and S, substituted or unsubstituted C 6-10 aryl and substituted or unsubstituted C 5-10 heteroaryl comprising 1-3 heteroatoms selected from N, O and S, and

wherein R 1 and R 2 are each independently selected from the group consisting of —H, substituted or unsubstituted C 1-10 alkyl, substituted or unsubstituted C 2-10 alkenyl, substituted or unsubstituted C 3-10 cycloalkyl, substituted or unsubstituted C 5-10 cycloalkenyl, substituted or unsubstituted C 1-10 alkoxy, substituted or unsubstituted C 2-10 alkenyloxy, substituted or unsubstituted 3-10-membered saturated or unsaturated monocyclic heterocyclic ring comprising 1-3 heteroatoms selected from N, O and S, substituted or unsubstituted C 6-10 aryl and substituted or unsubstituted C 5-10 heteroaryl comprising 1-3 heteroatoms selected from N, O and S,

wherein the substitution refers to substitution by at least one group selected from the group consisting of halogen, hydroxyl, cyano, amino, carboxyl, C 2-10 hydrocarbyl ether, nitro, C 1-10 sulfonyl, C 1-10 hydrocarbyl sulfonamide, C 6-10 aryl, C 5-10 heteroaryl comprising 1-3 heteroatoms selected from N, O and S, C 1-10 straight or branched chain alkyl, C 1-10 straight or branched chain alkenyl, C 1-10 hydrocarbyl acyl, C 1-10 hydrocarbyl acyloxy, C 1-10 hydrocarbyl amide, C 1-10 hydrocarbyl acyl amide, ureido, (C 1-10 alky) 1-2 amino, C 1-10 hydrocarbyl ester, phenoxy, benzyloxy, C 3-10 cycloalkyl, C 5-10 cycloalkenyl, C 1-10 alkoxy, C 1-10 alkenyloxy, C 1-10 alkylthiol and C 1-10 haloalkyl.

2. The compound, or a pharmaceutically acceptable salt or stereoisomer thereof, of claim 1 , wherein R′ is selected from the group consisting of —H, —C(O)R 1 , —C(O)NR 1 R 2 , —CO 2 R 1 , substituted or unsubstituted C 1-10 alkyl, substituted or unsubstituted C 2-10 alkenyl, substituted or unsubstituted C 6-10 aryl and substituted or unsubstituted C 5-10 heteroaryl comprising 1-3 heteroatoms selected from N, O and S, and

wherein R 1 and R 2 are each independently selected from the group consisting of —H, substituted or unsubstituted C 1-10 alkyl, substituted or unsubstituted C 2-10 alkenyl, substituted or unsubstituted C 3-7 cycloalkyl, substituted or unsubstituted C 5-7 cycloalkenyl, substituted or unsubstituted C 1-10 alkoxy, substituted or unsubstituted 5-7-membered saturated or unsaturated monocyclic heterocyclic ring comprising 1˜3 heteroatoms selected from N, O and S, substituted or unsubstituted C 6-10 aryl and substituted or unsubstituted C 5-10 heteroaryl comprising 1-3 heteroatoms selected from N, O and S,

wherein the substitution refers to substitution by at least one group selected from the group consisting of halogen, hydroxyl, cyano, amino, nitro, C 6-10 aryl, C 1-10 straight or branched chain alkyl, C 1-10 hydrocarbyl acyloxy, (C 1-10 alky) 1-2 amino, C 1-10 hydrocarbyl ester, phenoxy, benzyloxy, C 3-7 cycloalkyl, C 1-10 alkoxy and C 1-10 haloalkyl.

3. The compound, or a pharmaceutically acceptable salt or stereoisomer thereof, of claim 1 , wherein R′ is —C(O)R 1 , wherein R 1 is selected from the group consisting of substituted or unsubstituted C 3-6 alkyl, substituted or unsubstituted C 3-6 cycloalkyl, substituted or unsubstituted 5-6-membered saturated or unsaturated monocyclic heterocyclic ring comprising 1-2 heteroatoms selected from N, O and S, and substituted or unsubstituted phenyl,

wherein the substitution refers to substitution by at least one group selected from the group consisting of halogen, hydroxyl, cyano, amino, nitro, phenyl, C 1-3 straight or branched chain alkyl, (C 1-3 alky) 1-2 amino.

4. The compound, or a pharmaceutically acceptable salt or stereoisomer thereof, of claim 1 , wherein R is selected from the group consisting of hydrogen, fluoro, chloro, bromo, nitro, and amino; and X 1 , X 2 are —CH, respectively.

5. The compound, or a pharmaceutically acceptable salt or stereoisomer thereof, of claim 4 , wherein R 1 and R 2 are independently selected from the group consisting of ethyl, propyl, butyl, pentyl, cyclopropyl, cyclobutyl, cyclohexyl, phenyl, pyrrolidinyl and piperidinyl optionally substituted by one or two substituents selected from fluoro, chloro, nitro, amino, methylamino, dimethylamino, methyl and phenyl.

6. A compound, or a pharmaceutically acceptable salt or stereoisomer thereof, wherein the compound is selected from the following compounds:

4-(2-fluoro-(4-(1-benzyloxycarbonyl-piperidine)carbonylpiperazine-1-carbonyl)phen oxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(4-nitrobenzoyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(5-methylisoxazole-4-carbonyl)piperazine-1-carbonyl)phenoxy-2H-phthalazin-1-one,

4-(2-fluoro-5-(4-oxo-3,4-2H-phthalazine-1-yl-oxyl)benzoyl)-N-phenylpiperazine-1-formamide,

5-chloro-4-(4-fluoro-3-(4-(4-fluorobenzoyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

5-chloro-4-(4-fluoro-3-(4-benzoyl piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(2-methylthiazole-4-carbonyl)piperazine-1-carbonyl)phenoxy-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(4-fluorophenyl)piperazine-1-carbonyl)phenoxy)-5-nitro-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(4-fluorobenzoyl)piperazine-1-carbonyl)phenoxy)-5-nitro-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-benzoyl piperazine-1-carbonyl)phenoxy)-5-nitro-2H-phthalazin-1-one,

5-nitro-4-(2-fluoro-(4-(1-benzyloxycarbonyl-piperidine)carbonylpiperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(4-nitrobenzoyl)piperazine-1-carbonyl)phenoxy)-5-nitro-2H-phthalazin-1-one,

N-cyclohexyl-4-(2-fluoro-5-(4-oxo-3,4-2H-phthalazine-1-yl-oxyl)benzoyl)piperazine-1-formamide,

4-(3-(4-acetyl piperazine-1-carbonyl)-4-fluorophenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(thiazole-4-carbonyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(2-fluoro-(4-(2-benzyloxycarbonyl-piperidine)carbonylpiperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(2-fluoro-(4-(3-benzyloxycarbonyl-piperidine)carbonylpiperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(4-oxocyclohexanecarbonyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(4-cyanobenzoyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

(R)-4-(4-fluoro-3-(4-(2-phenylpropionyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(3-(4-(cyclopropanecarbonyl)piperazine-1-carbonyl)-4-fluorophenoxy)-2H-phthalazin-1-one,

1-(4-(2-fluoro-5-(4-oxo-3-1,4-dihydronaphthyridin-1-yl-oxyl)benzoyl)piperazine-1-yl)propane-1,2-phthalazinedione,

4-(4-fluoro-3-(4-(5-methylisoxazole-3-carbonyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(2,2,2-trifluoroacetyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(3,3,3-trifluoropropionyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-pivaloylpiperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(2-methoxyacetyl)piperazine-1-carbonyl)phenoxy-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(2-cyanobenzoyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(2-fluoro-5-(4-oxo-3,4-2H-phthalazin-1-yl-oxyl)benzoyl)-N-isopropyl-1-formamide,

4-(3-(4-(2-ethoxyacetyl)piperazine-1-carbonyl)-4-fluorophenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-isonicotinoylpiperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(3-(4-(2-ethylbutyryl)piperazine-1-carbonyl)-4-fluorophenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(4,4-difluoropiperidine-1-carbonyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(thiophene-2-carbonyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(3-hydroxypropyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-isobutyrylpiperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(2-fluoro-5-(4-oxo-3,4-2H-phthalazin-1-yl-oxyl)benzoyl)-N, N-dimethylpiperazine-1-formamide,

4-(4-fluoro-3-(4-(3-trifluoromethyl-4-methyl-benzoyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(3-(4-acryloylpiperazine-1-carbonyl)-4-fluorophenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(2-hydroxypropionyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(3-(4-(4-(dimethylamino)benzoyl)piperazine-1-carbonyl)-4-fluorophenoxy)-2H-phthalazin-1-one,

4-(3-(4-(3-(dimethylamino)benzoyl)piperazine-1-carbonyl)-4-fluorophenoxy)-2H-phthalazin-1-one,

4-(3-(4-tertbutylpiperazine-1-carbonyl)-4-fluorophenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(furan-2-carbonyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-isopropylpiperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(3-(4-allylpiperazine-1-carbonyl)-4-fluorophenoxy)-2H-phthalazin-1-one,

4-(3-(4-3-cyanobenzoylpiperazine-1-carbonyl)-4-fluorophenoxy)-2H-phthalazin-1-one,

4-(3-(4-(1H-pyrazole-1-carbonyl)piperazine-1-carbonyl)-4-fluorophenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(morpholine-4-carbonyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(pyrrolidine-1-carbonyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(piperidine-1-carbonyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(3-nitrobenzoyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(2-nitrobenzoyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

(E)-4-(3-(4-but-2-enoylpiperazine-1-carbonyl)-4-fluorophenoxy-)2H-phthalazin-1-one,

4-(4-fluoro-3-(4-methyl piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(oxazole-4-carbonyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(2-hydroxyethyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(3-(4-(1H-1,2,4-triazole-1-carbonyl)piperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one,

(R)-4-(4-fluoro-3-(4-(tetrahydrofuran-2-carbonyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(tetrahydrofuran-2-carbonyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

N-(4,4-difluorocyclohexyl)-4-(2-fluoro-5-(4-oxo-3,4-dihydro-phthalazin-1-yl-oxyl)benzoyl)piperazine-1-formamide,

N-cyclopropyl-4-(2-fluoro-5-(4-oxo-3,4-dihydro-phthalazine-1-yl-oxyl)benzoyl)piperazine-1-formamide,

4-(3-(4-(1H-imidazole-1-carbonyl)piperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one,

4-(3-(4-(cyclohexanecarbonyl)piperazine-1-carbonyl-4-fluorophenoxy)2H-phthalazin-1-one,

4-(4-fluoro-3-(4-propionylpiperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(3-(4-(cyclopentylcarbonyl)piperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one,

5-chloro-4-(2-fluoro-(4-(4-benzyloxycarbonyl-piperidine)carbonylpiperazine-1-carbonyl)phenoxy-2H-phthalazin-1-one,

4-(3-(4-benzoylpiperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one,

5-chloro-4-(4-fluoro-3-(4-(4-fluorophenyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

5-chloro-4-(4-fluoro-3-(4-(4-nitrobenzoyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(3-(4-(4,4-difluorocyclohexanecarbonyl)piperazine-1-carbonyl)-4-fluorophenoxy) 2H-phthalazin-1-one,

1-benzyloxycarbonyl-2-(4-(2-fluoro-5-(4-oxo-3,4-dihydronaphthyridin-1-yl-oxyl)benzoyl)piperazine-1-carbonyl)pyrrolidine,

4-(4-fluoro-3-(4-(pyrrolidine-2-carbonyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(4-fluorophenyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(tetrahydrofuran-3-carbonyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

N-(4-chlorophenyl)-4-(2-fluoro-5-(4-oxo-3,4-dihydronaphthyridin-1-yl-oxyl)benzoyl)piperazine-1-formamide,

N,N-diethyl-4-(2-fluoro-5-(4-oxo-3,4-dihydro-phthalazine-1-yl-oxyl)benzoyl)piperazine-1-formamide,

4-(4-fluoro-3-(4-(tetrahydropyran-4-carbonyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(4-(trifluoromethyl)benzoyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(4-fluorobenzoyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(4-fluorobenzyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one,

4-(4-fluoro-3-(piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(2-pyridyl)-formylpiperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

(S)-4-(4-fluoro-3-(4-(tetrahydrofuran-2-carbonyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(3-(4-(2-cyclopropylacetyl)piperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one,

4-(3-(4-(2-cyclopentylacetyl)piperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(1-(methylamino)cyclopropanecarbonyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(3-(4-(1-aminocyclopropanecarbonyl)piperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one,

4-(3-(4-(1-(dimethylamino)cyclobutanecarbonyl)piperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one,

4-(4-fluoro-3-(4-(1-(methylamino)cyclobutanecarbonyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one,

4-(3-(4-(1-aminocyclobutanecarbonyl)piperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one,

(R)-4-(3-(4-(1,2-dimethylpyrrolidine-2-carbonyl)piperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one, and

(R)-4-(4-fluoro-3-(4-(2-methylpyrrolidine-2-carbonyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one.

7. The compound, or a pharmaceutical acceptable salt or stereoisomer thereof, of claim 6 , wherein the compound is selected from the following compounds:

4-(4-fluoro-3-(4-(piperidine-1-carbonyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one;

4-(4-fluoro-3-(4-(2-nitrobenzoyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one;

4-(3-(4-(4,4-difluorocyclohexanecarbonyl)piperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one;

4-(3-(4-(1-(dimethylamino)cyclobutanecarbonyl)piperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one;

(R)-4-(4-fluoro-3-(4-(2-methylpyrrolidine-2-carbonyl)piperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one.

8. The compound, or a pharmaceutical acceptable salt or stereoisomer thereof, of claim 6 , wherein the compound is selected from the following compounds:

4-(4-fluoro-3-(4-pivaloylpiperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one;

4-(4-fluoro-3-(4-isopropylpiperazine-1-carbonyl)phenoxy)-2H-phthalazin-1-one;

4-(4-fluoro-3-(4-propionylpiperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one;

4-(3-(4-(1-aminocyclopropanecarbonyl)piperazine-1-carbonyl)-4-fluorophenoxy)2H-phthalazin-1-one;

4-(4-fluoro-3-(4-(1-(methylamino)cyclobutanecarbonyl)piperazine-1-carbonyl)phenoxy)2H-phthalazin-1-one.

9. The compound, or a pharmaceutical acceptable salt or stereoisomer thereof, of claim 6 , wherein the compound is 4-(3-(4-(2-ethylbutyryl)piperazine-1-carbonyl)-4-fluorophenoxy)-2H-phthalazin-1-one.

10. A pharmaceutical composition comprising an effective amount of the compound, or a pharmaceutically acceptable salt or stereoisomer thereof, of claim 1 , and a pharmaceutically acceptable carrier.