1-aryl- or 1-alkylsulfonyl-heterocyclylbenzazoles as 5-hydroxytryptamine-6 ligands

1. A compound of formula I

wherein

A is C or CR 10 ;

X is N and Y is CR 7 ; or X is CR 11 and Y is N;

R 1 is H, C 1 -C 6 alkylcarbonyl, C 1 -C 6 alkylcarbonyloxy or an C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynl or cycloheteroalkyl group each optionally substituted;

R 2 , R 3 , R 4 , R 5 and R 6 are each independently H, halogen, OH or an optionally substituted C 1 -C 6 alkyl group;

R 7 and R 11 are each independently H, halogen or an C 1 -C 6 alkyl, aryl, heteroaryl or C 1 -C 6 alkoxy group each optionally substituted;

R 8 is an C 1 -C 6 alkyl, aryl or heteroaryl group each optionally substituted;

R 9 is H, halogen or an C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 2 -C 6 alkenyl, aryl or heteroaryl group each optionally substituted;

R 10 is H, OH or an optionally substituted C 1 -C 6 alkoxy group;

m is an integer of 2;

n is 0 or an integer of 1, 2 or 3; and

represents a single bond or a double bond; or

a pharmaceutically acceptable salt thereof.

2. The compound according to claim 1 wherein X is CR 11 and Y is N.

3. The compound according to claim 1 wherein X is N and Y is CR 7 .

4. The compound according to claim 1 wherein R 8 is an optionally substituted phenyl group.

5. The compound according to claim 2 wherein R 2 , R 3 , R 4 , R 5 and R 6 are H.

6. The compound according to claim 5 wherein R 1 is H or a C 1 -C 6 alkyl optionally substituted.

7. A method for the treatment of a disorder of the central nervous system related to or affected by the 5-HT6 receptor in a patient in need thereof wherein said disorder is selected from the group consisting of schizophrenia, depression and anxiety which comprises administering to said patient a therapeutically effective amount of a compound of formula I

wherein

A is C or CR 10 ;

X is N and Y is CR 7 ; or X is CR 11 and Y is N;

R 1 is H, C 1 -C 6 alkylcarbonyl, C 1 -C 6 alkylcarbonyloxy or an C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynl or cycloheteroalkyl group each optionally substituted;

R 2 , R 3 , R 4 , R 5 and R 6 are each independently H, halogen, OH or an optionally substituted C 1 -C 6 alkyl group;

R 7 and R 11 are each independently H, halogen or an C 1 -C 6 alkyl, aryl, heteroaryl or C 1 -C 6 alkoxy group each optionally substituted;

R 8 is an C 1 -C 6 alkyl, aryl or heteroaryl group each optionally substituted;

R 9 is H, halogen or an C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 2 -C 6 alkenyl, aryl or heteroaryl group each optionally substituted;

R 10 is H, OH or an optionally substituted C 1 -C 6 alkoxy group;

m is an integer of 2;

n is 0 or an integer of 1, 2 or 3; and

represents a single bond or a double bond; or

a pharmaceutically acceptable salt thereof.

8. The method according to claim 7 wherein said disorder is schizophrenia.

9. The method according to claim 7 wherein said disorder is depression.

10. The method according to claim 7 wherein said disorder is anxiety.

11. A pharmaceutical composition which comprises a pharmaceutically acceptable carrier and an effective amount of a compound of formula I

wherein

A is C or CR 10 ;

X is N and Y is CR 7 ; or X is CR 11 and Y is N;

R 1 is H, C 1 -C 6 alkylcarbonyl, C 1 -C 6 alkylcarbonyloxy or an C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynl or cycloheteroalkyl group each optionally substituted;

R 2 , R 3 , R 4 , R 5 and R 6 are each independently H, halogen, OH or an optionally substituted C 1 -C 6 alkyl group;

R 7 and R 11 are each independently H, halogen or an C 1 -C 6 alkyl, aryl, heteroaryl or C 1 -C 6 alkoxy group each optionally substituted;

R 8 is an C 1 -C 6 alkyl, aryl or heteroaryl group each optionally substituted;

R 9 is H, halogen or an C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 2 -C 6 alkenyl, aryl or heteroaryl group each optionally substituted;

R 10 is H, OH or an optionally substituted C 1 -C 6 alkoxy group;

m is an integer of 2;

n is 0 or an integer of 1, 2 or 3; and

represents a single bond or a double bond; or

a pharmaceutically acceptable salt thereof.

12. The composition according to claim 11 wherein R 8 is an optionally substituted phenyl group.

13. The composition according to claim 11 wherein X is CR 11 and Y is N.

14. The composition according to claim 11 wherein X is N and Y is CR 7 .

15. The compound according to claim 6 wherein R 11 is H or a C 1 -C 6 alkyl.

16. The compound according to claim 15 wherein R 8 is an optionally substituted phenyl group.

17. The compound according to claim 3 wherein R 2 , R 3 , R 4 , R 5 and R 6 are H.

18. The compound according to claim 17 wherein R 1 is H or C 1 -C 6 alkyl.

19. The compound according to claim 18 wherein R 7 is H or C 1 -C 6 alkyl.

20. The compound according to claim 19 wherein R 8 is an optionally substituted phenyl group.