Indazole derivatives

1. A compound represented by the following formula [I] or a pharmaceutically acceptable salt thereof:

wherein the ring X is a benzene ring or a pyridine ring;

R 1 and R 2 are the same or different and are a hydrogen atom or an alkyl group; or

R 1 and R 2 are bonded together to form an unsubstituted cycloalkane ring;

R 3 is a hydrogen atom, a substituted alkyl group, an unsubstituted alkenyl group, a carboxyl group or an ester or an amide thereof, an amino group or a cyano group, wherein the substituted alkyl group is an alkyl group substituted with one or more groups selected from the group consisting of a hydroxyl group and a hydroxyimino group;

R 4 is a hydrogen atom, a hydroxyl group, a substituted or unsubstituted alkoxy group, an unsubstituted alkenyloxy group, an unsubstituted cycloalkyloxy group, a substituted or unsubstituted alkyl group, an unsubstituted alkenyl group, an unsubstituted cycloalkyl group, an amino group, a substituted or unsubstituted alkylamino group, a nitro group, a cyano group or a monocyclic heterocycle group, wherein the substituted alkoxy group is an alkoxy group substituted with one or more groups selected from the group consisting of a halogen atom and a cycloalkyl group, the substituted alkyl group is an alkyl group substituted with one or more hydroxyl groups and the substituted alkylamino group is an alkylamino group substituted with one or more aryl groups; and

R 5 is a halogen atom or a hydrogen atom.

2. The compound according to claim 1 , wherein the ring X is a benzene ring or a pyridine ring;

R 1 and R 2 are the same or different and are a hydrogen atom, a methyl group or an ethyl group; or R 1 and R 2 are bonded together to form a cyclopentane ring;

R 3 is a hydrogen atom, a hydroxymethyl group, a hydroxyiminomethyl group, a 1-methylvinyl group, a carboxyl group, a methoxycarbonyl group, an aminocarbonyl group, an amino group or a cyano group;

R 4 is a hydrogen atom, a hydroxyl group, a methoxy group, an ethoxy group, a n-propyloxy group, a n-butyloxy group, an isopropyloxy group, a difluoromethoxy group, a 2-fluoroethoxy group, a 2,2,2-trifluoroethoxy group, an allyloxy group, a cyclopropyloxy group, a cyclopropylmethyloxy group, an ethyl group, a vinyl group, a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a cyclopropyl group, an amino group, a methylamino group, a dimethylamino group, a diethylamino group, a benzylamino group, a nitro group, a cyano group, a pyrrolidine ring, a pyrrole ring, a pyrazole ring, an oxazole ring, an isoxazole ring, a piperidine ring, a pyridine ring or a morpholine ring; and

R 5 is a chlorine atom or a hydrogen atom,

or a pharmaceutically acceptable salt thereof.

3. The compound according to claim 1 , wherein the ring X is a benzene ring or a pyridine ring;

R 1 and R 2 are the same or different and are a hydrogen atom, a methyl group or an ethyl group; or R 1 and R 2 are bonded together to form a cyclopentane ring;

R 3 is a hydrogen atom;

R 4 is a hydroxyl group, a methoxy group, an ethoxy group, a n-propyloxy group, a n-butyloxy group, an isopropyloxy group, a difluoromethoxy group, a 2-fluoroethoxy group, a 2,2,2-trifluoroethoxy group, an allyloxy group, a cyclopropyloxy group, a cyclopropylmethyloxy group, an ethyl group, a vinyl group, a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a cyclopropyl group, an amino group, a methylamino group, a dimethylamino group, a diethylamino group, a benzylamino group, a nitro group, a cyano group, a pyrrolidine ring, a pyrrole ring, a pyrazole ring, an oxazole ring, an isoxazole ring, a piperidine ring, a pyridine ring or a morpholine ring; and

R 5 is a chlorine atom or a hydrogen atom,

or a pharmaceutically acceptable salt thereof.

4. The compound according to claim 1 , wherein the ring X is connected at the 5-position of the indazole ring, or a pharmaceutically acceptable salt thereof.

5. The compound according to claim 1 , wherein when the ring X is a benzene ring, the ring X is connected to the 5-position of the indazole ring and the

group is connected to the 4-position of the benzene ring; or when the ring X is a pyridine ring, the ring X is connected to the 5-position of the indazole ring and

the

group is connected to the 5-position of the pyridine ring,

or a pharmaceutically acceptable salt thereof.

6. The compound according to claim 2 , wherein the ring X is connected at the 5-position of the indazole ring, or a pharmaceutically acceptable salt thereof.

7. The compound according to claim 2 , wherein when the ring X is a benzene ring, the ring X is connected to the 5-position of the indazole ring and the

group is connected to the 4-position of the benzene ring; or when the ring X is a pyridine ring, the ring X is connected to the 5-position of the indazole ring and

the

group is connected to the 5-position of the pyridine ring,

or a pharmaceutically acceptable salt thereof.

8. The compound according to claim 3 , wherein the ring X is connected at the 5-position of the indazole ring, or a pharmaceutically acceptable salt thereof.

9. The compound according to claim 3 , wherein when the ring X is a benzene ring, the ring X is connected to the 5-position of the indazole ring and the

group is connected to the 4-position of the benzene ring; or when the ring X is a pyridine ring, the ring X is connected to the 5-position of the indazole ring and

the

group is connected to the 5-position of the pyridine ring,

or a pharmaceutically acceptable salt thereof.

10. A compound selected from the group consisting of

5-[4-(1-amino-1-methylethyl)phenyl]-1H-indazole,

1-acetyl-5-[4-(1-amino-1-methylethyl)phenyl]-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-nitro-1H-indazole,

4-amino-5-[4-(1-amino-1-methylethyl)phenyl]-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-benzylamino-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-methylamino-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-3-methoxycarbonyl-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-3-carboxy-1H-indazole,

3-aminocarbonyl-5-[4-(1-amino-1-methylethyl)phenyl]-1H-indazole,

3-amino-5-[4-(1-amino-1-methylethyl)phenyl]-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-3-hydroxyiminomethyl-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-3-cyano-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-3-hydroxymethyl-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-3-(1-methylvinyl)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-dimethylamino-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-nitro-1H-indazole,

4-(N-acetylamino)-5-[4-(1-amino-1-methylethyl)-phenyl]-1H-indazole,

5-[4-(aminomethyl)phenyl]-4-nitro-1H-indazole,

4-amino-5-[4-(aminomethyl)phenyl]-1H-indazole,

4-amino-5-[4-(1-aminocyclopentyl)phenyl]-1H-indazole,

4-amino-5-[4-(1-amino-1-ethylpropyl)phenyl]-1H-indazole,

5-[4-(aminomethyl)phenyl]-4-dimethylamino-1H-indazole,

5-[4-(1-aminocyclopentyl)phenyl]-4-dimethylamino-1H-indazole,

5-[4-(1-amino-1-ethylpropyl)phenyl]-4-dimethyl-amino-1H-indazole,

5-[4-(1-aminoethyl)phenyl]-4-dimethylamino-1H-indazole,

5-[5-(1-amino-1-methylethyl)-3-chloropyridin-2-yl]-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-ethyl-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-cyclopropyl-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-vinyl-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-diethylamino-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(2-hydroxyethyl)-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-(2-hydroxyethyl)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(1-hydroxyethyl)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-hydroxymethyl-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-cyano-1H-indazole,

6-[4-(1-amino-1-methylethyl)phenyl]-1H-indazole,

1-acetyl-6-[4-(1-amino-1-methylethyl)phenyl]-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(pyrrol-1-yl)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-isopropoxy-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(piperidin-1-yl)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(pyrrolidin-1-yl)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(morpholin-4-yl)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-methoxy-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-methoxy-1H-indazole,

5-[5-(1-aminocyclopentyl)pyridin-2-yl]-4-methoxy-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-ethoxy-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-hydroxy-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-ethoxy-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-isopropoxy-1H-indazole,

5-[5-(1-amino-1-ethylpropyl)pyridin-2-yl]-4-methoxy-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-n-propoxy-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-difluoromethoxy-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(2,2,2-trifluoroethoxy)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-n-butoxy-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(2-fluoroethoxy)-1H-indazole,

4-allyloxy-5-[4-(1-amino-1-methylethyl)phenyl]-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-n-propoxy-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-difluorornethoxy-1H-indazole,

5-[5-(1-amino-1-ethylpropyl)pyridin-2-yl]-4-ethoxy-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(pyridin-4-yl)-1H-1-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(pyridin-3-yl)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(pyridin-2-yl)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(pyrazol-4-yl)-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-(pyrazol-4-yl)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(oxazol-5-yl)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(pyrazol-3-yl)-1H-indazole,

5-[4-(1-amino-1-methylethyl)phenyl]-4-(isoxazol-5-yl)-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-hydroxyl-1H-indazole,

5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-cyclopropyloxy-1H-indazole,

5-[5-(1-amino-1-ethylpropyl)pyridin-2-yl]-4-cyclopropyloxy-1H-indazole,

5-[4-(1-amino-1-ethylpropyl)phenyl]-4-difluoromethoxy-1H-indazole and 5-[5-(1-amino-1-methylethyl)pyridin-2-yl]-4-cyclopropylmethyloxy-1H-indazole,

or a pharmaceutically acceptable salt thereof.

11. A pharmaceutical composition comprising a pharmaceutically effective amount of the compound according to any of claims 1 to 10 or a pharmaceutically acceptable salt thereof in combination with a pharmaceutically acceptable carrier.