6-heterocyclic-imidazo[1,2-α]pyridine-2-carboxamide derivatives, preparation and therapeutic use thereof

1. A compound of formula (I):

wherein:

X represents a phenyl group optionally substituted with one or more groups chosen, independently of each other, from the following atoms or groups: halogen, (C 1 -C 6 )alkoxy, (C 1 -C 6 )alkyl, NRaRb, cyano, and (C 1 -C 6 )alkoxycarbonyl, the groups (C 1 -C 6 )alkyl and (C 1 -C 6 )alkoxy being optionally substituted with one or more halogen atoms;

R 1 represents a hydrogen atom, a halogen, a group (C 1 -C 6 )alkoxy, a group (C 1 -C 6 )alkyl or a group NRaRb; the alkyl and alkoxy groups possibly being substituted with one or more halogen, hydroxyl, amino, or a group (C 1 -C 6 )alkoxy;

R 2 represents an unsaturated, partially saturated or totally saturated aromatic heterocyclic group, optionally substituted with one or more groups chosen, independently of each other, from the following atoms or groups: hydroxyl, (C 1 -C 6 )alkoxy, halogen, cyano, NRaRb, —CO—R 5 , —CO—NR 6 R 7 , —CO—O—R 8 , —NR 9 —CO—R 10 (C 3 -C 7 )cycloalkyl(C 1 -C 6 )alkyl, (C 3 -C 7 )cycloalkyl(C 1 -C 6 )alkoxy, a group (C 1 -C 6 )alkyl, optionally substituted with one or more hydroxyl or NRaRb, an oxido group, whereby R 2 is linked to the imidazo[1,2-a]pyridine moiety of formula (I) via a carbon-carbon bond;

R 3 represents a hydrogen atom, a group (C 1 -C 6 )alkyl, a group (C 1 -C 6 )alkoxy or a halogen atom;

R 4 represents a hydrogen atom, a group (C 1 -C 4 )alkyl, a group (C 1 -C 4 )alkoxy or a fluorine atom;

R 5 represents a hydrogen atom, a phenyl group or a group (C 1 -C 6 )alkyl;

R 6 and R 7 , which may be identical or different, represent a hydrogen atom or a group (C 1 -C 6 )alkyl or form, with the nitrogen atom, a 4- to 7-membered ring optionally including another heteroatom chosen from N, O and S;

R 8 represents a group (C 1 -C 6 )alkyl;

R 9 and R 10 , which may be identical or different, represent a hydrogen atom or a group (C 1 -C 6 )alkyl;

Ra and Rb are, independently of each other, hydrogen or (C 1 -C 6 )alkyl or form, with the nitrogen atom that bears them, a 4- to 7-membered ring, optionally including another heteroatom chosen from N, O and S;

or an acid addition salt thereof;

with the exception of N-(4-bromophenyl)-6-(1-methyl-2-piperidinyl)imidazo[1,2-a]pyridine-2-carboxamide.

2. The compound of formula (I) according to claim 1 , wherein:

X represents a phenyl group optionally substituted with one or more halogen atoms or cyano groups;

or an acid addition salt thereof.

3. The compound of formula (I) according to claim 1 , wherein:

R 2 represents a pyrrole, furan, thiophene, pyrazole, imidazole, triazole, tetrazole, oxazole, isoxazole, oxadiazole, thiazole, isothiazole, thiadiazole, pyridine, pyrimidine, pyrazine, pyridazine or triazine group, optionally substituted with one or more groups chosen from the following atoms or groups: hydroxyl, (C 1 -C 6 )alkoxy, oxido, halogen, —NRaRb, and (C 1 -C 6 )alkyl which is itself optionally substituted with a hydroxyl group; and

Ra and Rb are, independently of each other, hydrogen or (C 1 -C 6 )alkyl;

or an acid addition salt thereof.

4. The compound of formula (I) according to claim 1 , wherein:

R 2 represents a pyrrole, furan, thiophene, pyrazole, imidazole, triazole, tetrazole, oxazole, isoxazole, oxadiazole, thiazole, isothiazole, thiadiazole, pyridine, pyrimidine, pyrazine, pyridazine or triazine group, optionally substituted with one or more groups chosen from the following atoms or groups: hydroxyl, (C 1 -C 6 )alkoxy, oxido, halogen, —NRaRb, and (C 1 -C 6 )alkyl which is itself optionally substituted with a hydroxyl group; and

Ra and Rb are, independently of each other, hydrogen or (C 1 -C 6 )alkyl;

or an acid addition salt thereof.

5. The compound of formula (I) according to claim 1 , wherein:

R 2 represents an indole, isoindole, benzimidazole, indazole, indolizine, benzofuran, isobenzofuran, benzothiophene, benzo[c]thiophen, pyrrolopyridine, imidazopyridine, pyrazolopyridine, triazolopyridine, tetrazolopyridine, pyrrolopyrimidine, imidazopyrimidine, pyrazolopyrimidine, triazolopyrimidine, tetrazolopyrimidine, pyrrolopyrazine, imidazopyrazine, pyrazolopyrazine, triazolopyrazine, tetrazolopyrazine, pyrrolopyridazine, imidazopyridazine, pyrazolopyridazine, triazolopyridazine, tetrazolopyridazine, pyrrolotriazine, imidazotriazine, pyrazolotriazine, triazolotriazine, tetrazolotriazine, furopyridine, furopyrimidine, furopyrazine, furopyridazine, furotriazine, oxazolopyridine, oxazolopyrimidine, oxazolopyrazine, oxazolopyridazine, oxazolotriazine, isoxazolopyridine, isoxazolopyrimidine, isoxazolopyrazine, isoxazolopyridazine, isoxazolotriazine, oxadiazolopyridine, oxadiazolopyrimidine, oxadiazolopyrazine, oxadiazolopyridazine, oxadiazolotriazine, benzoxazole, benzisoxazole, benzoxadiazole, thienopyridine, thienopyrimidine, thienopyrazine, thienopyridazine, thienotriazine, thiazolopyridine, thiazolopyrimidine, thiazolopyrazine, thiazolopyridazine, thiazolotriazine, isothiazolopyridine, isothiazolopyrimidine, isothiazolopyrazine, isothiazolopyridazine, isothiazolotriazine, thiadiazolopyridine, thiadiazolopyrimidine, thiadiazolopyrazine, thiadiazolopyridazine, thiadiazolotriazine, benzothiazole, benzoisothiazole or benzothiadiazole group, optionally substituted with one or more groups chosen from the following atoms or groups: hydroxyl, (C 1 -C 6 )alkoxy, oxido, halogen, —NRaRb, and (C 1 -C 6 )alkyl which is itself optionally substituted with a hydroxyl group; and

Ra and Rb are, independently of each other, hydrogen or (C 1 -C 6 )alkyl;

or an acid addition salt thereof.

6. The compound of formula (I) according to claim 1 , wherein:

R 2 represents a dioxolane, pyridine, imidazole, pyrazole, triazole, pyrrole, furan, oxazole, indole, imidazoline, thiophene, pyrazine, pyrimidine or thiazole group optionally substituted with one or more groups chosen from the following atoms or groups: hydroxyl, (C 1 -C 6 )alkoxy, oxido, halogen, —NRaRb, and (C 1 -C 6 )alkyl which is itself optionally substituted with a hydroxyl group, and

Ra and Rb are, independently of each other, hydrogen or (C 1 -C 6 )alkyl,

or an acid addition salt thereof.

7. The compound of formula (I) according to claim 1 , wherein R 1 represents a hydrogen atom or a group (C 1 -C 6 )alkyl;

or an acid addition salt thereof.

8. The compound of formula (I) according to claim 1 , wherein R 3 and R 4 represent a hydrogen atom;

or an acid addition salt thereof.

9. The compound of formula (I) according to claim 1 , wherein:

X represents a phenyl group optionally substituted with one or more fluorine or chlorine atoms or with a cyano group;

R 2 represents a dioxolane, pyridine, imidazole, pyrazole, triazole, pyrrole, furan, oxazole, indole, imidazoline, thiophene, pyrazine, pyrimidine or thiazole group, optionally substituted with one or more hydroxyl, methyl, hydroxymethyl, methoxy, halogen, NH 2 , (C 1 -C 6 )alkyl or oxido groups,

R 1 represents a hydrogen atom or a methyl group; and

R 3 and R 4 represent a hydrogen atom;

or an acid addition salt thereof.

10. The compound of formula (I) according to claim 1 , selected from the group consisting of:

6-(1,3-Dioxolan-2-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

N-Phenyl-6-(pyrid-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-Phenyl-6-(pyrid-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

6-[5-(Hydroxymethyl)pyrid-3-yl]-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

6-[4-(Hydroxymethyl)pyrid-2-yl]-N-phenylimidazo[1,2-a]pyridine-2-carboxamide and the hydrochloride (1:1) thereof;

6-(6-Aminopyrid-2-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide and the hydrochloride (1:1) thereof;

6-(1H-Imidazol-4-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide and the hydrochloride (1:1) thereof;

N-Phenyl-6-(1H-pyrazol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-Phenyl-6-(1H-1,2,4-triazol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-Phenyl-6-(1H-pyrrol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

6-(2-Methyl-1H-imidazol-4-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

6-(3-Furyl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

6-(1H-Imidazol-1-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide and the trifluoroacetate (1:1) thereof;

6-(Oxazol-5-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

6-(2-Aminothiazol-4-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

6-(2-Methyl-1,3-dioxolan-2-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

6-(4,5-Dihydro-1H-imidazol-2-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide and the hydrochloride (1:1) thereof;

6-(6-Methoxypyrid-2-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

5-Methyl-N-phenyl-6-(pyrid-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

6-(2-Amino-1H-imidazol-4-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide and the trifluoroacetate (1:1) thereof;

6-(2-Aminothiazol-5-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

6-(6-Hydroxypyrid-2-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

N-Phenyl-6-(1H-1,2,3-triazol-4-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3,5-Difluorophenyl)-6-(furan-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3-Fluorophenyl)-6-(furan-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

6-(2-Furyl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

6-[6-(Hydroxymethyl)pyrid-2-yl]-N-phenylimidazo[1,2-a]pyridine-2-carboxamide and the hydrochloride (1:1) thereof;

6-(1-Oxidopyrid-3-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide and the hydrochloride (1:1) thereof;

N-Phenyl-6-(1H-pyrazol-4-yl)imidazo[1,2-a]pyridine-2-carboxamide;

6-(1H-Imidazol-2-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide hydrochloride (1:1);

6-(1-Methyl-1H-imidazol-4-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

6-(Oxazol-2-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

N-(3,5-Difluorophenyl)-6-(pyrid-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-Phenyl-6-(pyrid-4-yl)imidazo[1,2-a]pyridine-2-carboxamide;

6-(1H-Indol-3-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

N-Phenyl-6-(thiophen-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-Phenyl-6-(pyrazin-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

6-(1-Oxidopyrid-2-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

N-Phenyl-6-(pyrimidin-5-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-Phenyl-6-(thien-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

6-(5-Fluoro-2-furyl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

N-(3-Fluorophenyl)-6-(pyrid-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Fluorophenyl)-6-(pyrid-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,5-Difluorophenyl)-6-(pyrid-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,3-Difluorophenyl)-6-(pyrid-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

6-(6-Aminopyrid-2-yl)-N-(3-fluorophenyl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3-Fluorophenyl)-6-(1H-pyrrol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3-Fluorophenyl)-6-(1H-pyrazol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3-Fluorophenyl)-6-(furan-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3-Fluorophenyl)-6-(oxazol-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-Phenyl-6-(pyrimidin-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3-Fluorophenyl)-6-(1H-imidazol-4-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3-Fluorophenyl)-6-(1H-1,2,4-triazol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

6-(2-Aminothiazol-4-yl)-N-(3-fluorophenyl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3-Fluorophenyl)-6-(1H-1,2,3-triazol-4-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3-Fluorophenyl)-6-(1H-pyrazol-4-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3-Fluorophenyl)-6-[5-(hydroxymethyl)furan-2-yl]imidazo[1,2-a]pyridine-2-carboxamide;

6-[2-(Hydroxymethyl)-1H-imidazol-4-yl]-N-phenylimidazo[1,2-a]pyridine-2-carboxamide;

N-(3,5-Difluorophenyl)-6-(6-methylpyrid-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Chlorophenyl)-6-(pyrid-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3,5-Difluorophenyl)-6-(1H-pyrrol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Fluorophenyl)-6-(1H-pyrrol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,5-Difluorophenyl)-6-(1H-pyrrol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,3-Difluorophenyl)-6-(1H-pyrrol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3,5-Difluorophenyl)-6-(1H-pyrazol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Fluorophenyl)-6-(furan-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,5-Difluorophenyl)-6-(furan-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,3-Difluorophenyl)-6-(furan-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Chlorophenyl)-6-(furan-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,5-Difluorophenyl)-6-(oxazol-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Chlorophenyl)-6-(oxazol-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Fluorophenyl)-6-(furan-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,5-Difluorophenyl)-6-(furan-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,3-Difluorophenyl)-6-(furan-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Chlorophenyl)-6-(furan-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,3-Difluorophenyl)-6-[5-(hydroxymethyl)furan-2-yl]imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Fluorophenyl)-6-(1H-1,2,4-triazol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Chlorophenyl)-6-(1H-1,2,4-triazol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Cyanophenyl)-6-(pyrid-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

6-(6-Aminopyrid-2-yl)-N-(3,5-difluorophenyl)imidazo[1,2-a]pyridine-2-carboxamide and the dihydrochloride thereof;

6-(6-Aminopyrid-2-yl)-N-(2-fluorophenyl)imidazo[1,2-a]pyridine-2-carboxamide and the dihydrochloride thereof;

6-(6-Aminopyrid-2-yl)-N-(2,5-difluorophenyl)imidazo[1,2-a]pyridine-2-carboxamide and the dihydrochloride thereof;

6-(6-Aminopyrid-2-yl)-N-(2,3-difluorophenyl)imidazo[1,2-a]pyridine-2-carboxamide and the dihydrochloride thereof;

6-(6-Aminopyrid-2-yl)-N-(2-chlorophenyl)imidazo[1,2-a]pyridine-2-carboxamide and the dihydrochloride thereof;

N-(2-Chlorophenyl)-6-(1H-pyrrol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Fluorophenyl)-6-(1H-pyrazol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Chlorophenyl)-6-(1H-pyrazol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3,5-Difluorophenyl)-6-(furan-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3,5-Difluorophenyl)-6-(oxazol-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Fluorophenyl)-6-(oxazol-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,3-Difluorophenyl)-6-(oxazol-2-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3,5-Difluorophenyl)-6-[5-(hydroxymethyl)furan-2-yl]imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,5-Difluorophenyl)-6-[5-(hydroxymethyl)furan-2-yl]imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,3-Difluorophenyl)-6-(1H-imidazol-4-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,5-Difluorophenyl)-6-(1H-1,2,4-triazol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,3-Difluorophenyl)-6-(1H-1,2,4-triazol-3-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(3,5-Difluorophenyl)-6-(1H-1,2,3-triazol-4-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2-Fluorophenyl)-6-(1H-1,2,3-triazol-4-yl)imidazo[1,2-a]pyridine-2-carboxamide;

N-(2,5-Difluorophenyl)-6-(1H-1,2,3-triazol-4-yl)imidazo[1,2-a]pyridine-2-carboxamide; and

N-(2-Chlorophenyl)-6-(1H-1,2,3-triazol-4-yl)imidazo[1,2-a]pyridine-2-carboxamide;

or an acid addition salt thereof.

11. A pharmaceutical composition comprising a compound of formula (I) according to claim 1 , or a pharmaceutically acceptable salt of this compound, and also at least one pharmaceutically acceptable excipient.