1-imidazothiadiazolo-2H-pyrrol-5-one derivatives

1. A compound according to formula (I), or a pharmaceutically acceptable salt thereof,

wherein

R 1 is a C 1-4 alkyl or a C 3-5 cycloalkyl, either of which groups are optionally substituted by one or more halogen substituents;

R 2 is a C 1-4 alkyl substituted by one hydroxy or alkoxy substituent;

R 3 is a halogen; or C 1-4 alkyl or C 3-4 cycloalkyl, either of which groups are optionally substituted by one or more halogen atoms.

2. A compound according to claim 1 , or a pharmaceutically acceptable salt thereof, wherein R 2 is a C 1-4 alkyl substituted by a alkoxy substituent.

3. A compound according to claim 1 , or a pharmaceutically acceptable salt thereof, wherein R 3 is a C 1-4 alkyl substituted by one or more halogen atoms.

4. A compound according to claim 1 or a pharmaceutically acceptable salt thereof, wherein R 1 is n-propyl, 2,2-difluoropropyl, 3,3,3-trifluoropropyl, 2-chloro-2,2-difluoroethyl, a 2,2,2-trifluoroethyl, or 2,2-difluorocyclopropyl.

5. A compound according to claim 1 , or a pharmaceutically acceptable salt thereof, wherein R 1 is 3,3,3-trifluoropropyl, or 2,2-difluorocyclopropyl.

6. A compound according to claim 1 , or a pharmaceutically acceptable salt thereof, wherein R 2 is a hydroxymethyl or a methoxymethyl.

7. A compound according to claim 1 , or a pharmaceutically acceptable salt thereof wherein R 2 is a methoxymethyl.

8. A compound according to claim 1 , or a pharmaceutically acceptable salt thereof, wherein R3 is a methyl, a difluoromethyl, a chlorine or a trifluoromethyl group.

9. A compound according to claim 1 , or pharmaceutical acceptable salt thereof, wherein R3 is a methyl or difluoromethyl.

10. A compound according to claim 1 selected from the group consisting of:

1-[[2-(methoxymethyl)-6-(trifluoromethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-propyl-2H-pyrrol-5-one;

1-[[2-(methoxymethyl)-6-(trifluoromethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(2,2,2-trifluoroethyl)-2H-pyrrol-5-one;

1-[[2-(methoxymethyl)-6-(trifluoromethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(3,3,3-trifluoropropyl)-2H-pyrrol-5-one;

1-[[2-(methoxymethyl)-6-methyl-imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-propyl-2H-pyrrol-5-one;

1-[[6-chloro-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(2,2,2-trifluoroethyl)-2H-pyrrol-5-one;

1-[[6-chloro-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-propyl-2H-pyrrol-5-one;

1-[[6-chloro-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(3,3,3-trifluoropropyl)-2H-pyrrol-5-one;

1-[[6-(difluoromethyl)-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-propyl-2H-pyrrol-5-one;

1-[[6-(difluoromethyl)-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(2,2,2-trifluoroethyl)-2H-pyrrol-5-one;

1-[[6-(difluoromethyl)-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(2,2,2-trifluoroethyl)-2H-pyrrol-5-one;

1-[[2-(methoxymethyl)-6-methyl-imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(2,2,2-trifluoroethyl)-2H-pyrrol-5-one;

1-[[6-(difluoromethyl)-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(2,2,2-trifluoroethyl)-2H-pyrrol-5-one;

1-[[6-(1-fluorocyclopropyl)-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(2,2,2-trifluoroethyl)-2H-pyrrol-5-one;

3-(2-chloro-2,2-difluoro-ethyl)-1-[[2-(methoxymethyl)-6-(trifluoromethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-2H-pyrrol-5-one;

1-[[2-(methoxymethyl)-6-methyl-imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(3,3,3-trifluoropropyl)-2H-pyrrol-5-one;

1-[[6-(difluoromethyl)-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(3,3,3-trifluoropropyl)-2H-pyrrol-5-one;

3-(2,2-difluoropropyl)-1-[[2-(methoxymethyl)-6-(trifluoromethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-2H-pyrrol-5-one;

1-[[6-(difluoromethyl)-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(2,2-difluoropropyl)-2H-pyrrol-5-one;

3R-(2,2-difluorocyclopropyl)-1-[[2-(methoxymethyl)-6-(trifluoromethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-2H-pyrrol-5-one;

3S-(2,2-difluorocyclopropyl)-1-[[2-(methoxymethyl)-6-(trifluoromethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-2H-pyrrol-5-one;

1-[[2-(methoxymethyl)-6-methyl-imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3R-[2,2-difluorocyclopropyl]-2H-pyrrol-5-one;

1-[[2-(methoxymethyl)-6-methyl-imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3S-[2,2-difluorocyclopropyl]-2H-pyrrol-5-one;

1-[[6-(difluoromethyl)-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3R-[2,2-difluorocyclopropyl]-2H-pyrrol-5-one;

1-[[6-(difluoromethyl)-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3S-[2,2-difluorocyclopropyl]-2H-pyrrol-5-one;

3-(2,2-difluoropropyl)-1-[[2-(methoxymethyl)-6-methyl-imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-2H-pyrrol-5-one;

1-[[2-(hydroxymethyl)-6-methyl-imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(3,3,3-trifluoropropyl)-2H-pyrrol-5-one;

1-[[6-(difluoromethyl)-2-(hydroxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(3,3,3-trifluoropropyl)-2H-pyrrol-5-one; and

1-[[6-(difluoromethyl)-2-(hydroxymethyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl]methyl]-3-(2,2,2-trifluoroethyl)-2H-pyrrol-5-one.

11. A pharmaceutical composition comprising an effective amount of a compound according to claim 1 in combination with a pharmaceutically acceptable diluent or carrier.

12. A method for treatment of epilepsy, epileptogenesis, seizure disorders, convulsions comprising administering a compound according to claim 1 to a subject in need thereof.

13. A method for treatment of refractory seizures comprising administering a compound according to claim 1 to a subject in need thereof.