Indane derivatives

1. An indane compound according to formula I

wherein

L 1 is O, (CR 5 R 6 ) m , OCR 7 R 8 or CR 9 R 10 O;

L 2 is NR 11 SO 2 or SO 2 NR 12 ;

X 1 -X 4 are CR 1 ;

R 1 is H, C 1-6 alkyl, C 3-8 cycloalkyl, C 1-6 alkyloxy, halogen, CN, SC 1-6 alkyl, SOC 1-6 alkyl,

SO 2 C 1-6 alkyl, NR 13 SO 2 R 14 , CH 2 NR 15 SO 2 R 16 , CONR 17 R 18 , NR 19 COR 20 or

SO 2 NR 21 R 22 ,

said C 1-6 alkyl, C 3-8 cycloalkyl and C 1-6 alkyloxy being optionally substituted with one or more halogens with the proviso that each R 1 cannot simultaneously be H;

or two R 1 together form a fused 5- or 6-membered heteroaryl ring comprising 1-3 heteroatoms independently selected from O, S and N;

R 2 is C 1-6 alkyl, C 3-8 cycloalkyl, C 1-6 alkyloxy or CN, said C 1-6 alkyl, C 3-8 cycloalkyl and C 1-6 alkyloxy being substituted with one or more moiety independently selected from OH, C 1-6 alkyloxy and NR 23 R 24 ;

R 3 is H, C 1-6 alkyl C 3-8 cycloalkyl, C 1-6 alkyloxy, halogen or CN, said C 1-6 alkyl, C 3-8 cycloalkyl and C 1-6 alkyloxy being optionally substituted with one or more halogens;

R 4 is H, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 3-8 cycloalkyl, C 3-8 cycloalkylC 1-2 alkyl,

NR 25 R 26 , C 6-10 aryl or a 5-9 membered heteroaryl ring system comprising 1-3 heteroatoms independently selected from O, S and N, wherein said C 1-6 alkyl, C 3-8 cycloalkyl, C 6-10 aryl and 5-9 membered heteroaryl ring system are optionally substituted with one or more moieties independently selected from halogen, C 1-6 alkyl, hydroxy and C 1-6 alkyloxy, said C 1-6 alkyl, and C 1-6 alkyloxy being optionally substituted with 1-3 halogens;

R 5 -R 13 are independently H or C 1-6 alkyl;

R 14 and R 16 are independently C 1-6 alkyl;

R 15 , R 17 , R 18 and R 19 are independently H or C 1-6 alkyl;

R 20 is C 1-6 alkyl;

R 21 and R 22 are independently H or C 1-6 alkyl

R 23 and R 24 are independently H or C 1-4 alkyl or R 23 and R 24 together with the N to which they are bonded form a 4-6 membered saturated or unsaturated heterocyclic ring optionally comprising another heteroatomic moiety selected from O, S and N(R 27 ) p ;

R 25 and R 26 are independently H or C 1-4 alkyl or R 25 and R 26 together with the N to which they are bonded form a 4-6 membered saturated or unsaturated heterocyclic ring optionally comprising another heteroatomic moiety selected from O, S and N(R 28 ) q ;

R 27 and R 28 are independently H or C 1-4 alkyl;

m is 1-2;

n is 0 or 1;

p is 0 or 1;

q is 0 or 1;

Y 1 -Y 3 are CR 29 ;

R 29 is H or C 1-6 alkyl optionally substituted with one or more halogens;

or a pharmaceutically acceptable salt or solvate thereof, with the proviso that when L 1 is (CR 5 R 6 ) m and L 2 is a substituent at the 2-position, n cannot be 0.

2. The indane compound according to claim 1 or a pharmaceutically acceptable salt or solvate thereof, wherein R 1 is H, Cl, F, CF 3 , OCF 3 , CN, SO 2 CH 3 , SO 2 NHCH 3 , NHSO 2 CH 3 or CH 2 NHSO 2 CH 3 .

3. The indane compound according to claim 1 or a pharmaceutically acceptable salt or solvate thereof, wherein R 2 is methyl substituted with hydroxy or NR 23 R 24 , wherein R 23 and R 24 have the previously defined meanings.

4. The indane compound according to claim 1 or a pharmaceutically acceptable salt or solvate thereof, wherein R 3 is H.

5. The indane compound according to claim 1 or a pharmaceutically acceptable salt or solvate thereof, wherein R 4 is ethyl, isopropyl, cyclopropyl, tertiary-butyl or dimethylamino, wherein said ethyl, isopropyl, cyclopropyl and tertiary-butyl are optionally substituted with one or more halogens .

6. The indane compound according to claim 1 or a pharmaceutically acceptable salt or solvate thereof, wherein X 1 -X 4 are CH.

7. The indane compound according to claim 1 or a pharmaceutically acceptable salt or solvate thereof, wherein L 1 is CH 2 .

8. The indane compound according to claim 1 or a pharmaceutically acceptable salt or solvate thereof, wherein L 1 is O.

9. The indane compound according to claim 1 or a pharmaceutically acceptable salt or solvate thereof, wherein R 23 and R 24 are independently H or C 1-4 alkyl.

10. The indane compound according to claim 1 or a pharmaceutically acceptable salt or solvate thereof, wherein Y 1 -Y 3 are CH.

11. The indane compound according to claim 1 or a pharmaceutically acceptable salt or solvate thereof, wherein L 2 is NHSO 2 .

12. An indane compound according to claim 1 selected from:

or a pharmaceutically acceptable salt or solvate thereof.

13. A method for treating psychiatric diseases wherein an enhancement of synaptic responses mediated by AMPA receptors is required, the method comprising administering a therapeutically effective amount of an indane compound according to claim 1 or a pharmaceutically acceptable salt thereof.

14. A method for treating psychiatric diseases wherein an enhancement of synaptic responses mediated by AMPA receptors is required, the method comprising administering a therapeutically effective amount of an indane compound according to claim 12 or a pharmaceutically acceptable salt thereof.

15. A pharmaceutical composition comprising an indane compound according to claim 1 or a pharmaceutically acceptable salt thereof in admixture with one or more pharmaceutically acceptable auxiliaries.

16. A pharmaceutical composition comprising an indane compound according to claim 12 or a pharmaceutically acceptable salt thereof in admixture with one or more pharmaceutically acceptable auxiliaries.