N-phenyl- (piperazinyl or homopiperazinyl)-benzenesulfonamide or benzenesulfonyl-phenl-(piperazine or homopiperazine) compounds suitable for treating disorders that respond to modulation of the serotonin 5-HT

1. N-Phenyl-(piperazinyl or homopiperazinyl)-benzenesulfonamide or benzenesulfonyl-phenyl-(piperazine or homopiperazine) of formula (I) or (I′)

wherein

X is a bond or a group N-R 4;

R 1 is hydrogen or methyl;

R 2 is hydrogen or methyl;

R 3 is hydrogen, C 1 -C 3 alkyl, fluorine, C 1 -C 2 alkoxy or fluorinated C 1 -C 2 alkoxy;

R 4 is hydrogen, C 1 -C 4 alkyl, C 3 -C 4 cycloalkyl, or C 3 -C 4 cycloalkyl-CH 2 -;

R 5 is hydrogen, fluorine, chlorine, C 1 -C 2 alkyl, fluorinated C 1 -C 2 alkyl, C 1 -C 2 alkoxy or fluorinated C 1 -C 2 alkoxy;

R 6 is hydrogen, fluorine or chlorine; and

n is 1 or 2,

or a physiologically tolerated acid addition salt or an N-oxide thereof.

2. The compound as claimed in claim 1 , wherein R 5 is hydrogen, fluorine, C 1 -C 2 alkyl, fluorinated C 1 -C 2 alkyl, C 1 -C 2 alkoxy or fluorinated C 1 -C 2 alkoxy.

3. The compound of claim 1 , where R 1 is hydrogen.

4. The compound of claim 1 , wherein R 2 is hydrogen.

5. The compound of claim 1 , wherein R 2 is methyl.

6. The compound of claim 1 , wherein X is a group N—R 4 .

7. The compound of claim 1 , wherein n is 1.

8. The compound of claim 1 , wherein R 3 is methyl or methoxy.

9. The compound of claim 1 , wherein R 3 is hydrogen or fluorine.

10. The compound of claim 1 , wherein R 4 is hydrogen, C 1 -C 4 alkyl or cyclopropylmethyl.

11. The compound of claim 1 , wherein R 4 is hydrogen.

12. The compound of claim 1 , wherein R 5 is hydrogen.

13. The compound of claim 1 , wherein R 5 is methyl, methoxy or difluoromethoxy.

14. The compound of claim 1 , wherein R 5 is chlorine or fluorine.

15. The compound of claim 1 , wherein R 6 is hydrogen.

16. The compound of claim 1 , wherein R 5 and R 6 are hydrogen, R 3 is selected from the group consisting of C 1 -C 2 alkyl and C 1 -C 2 alkoxy, and R 4 is selected from the group consisting of hydrogen, C 1 -C 4 alkyl, or cyclopropylmethyl.

17. The compound of claim 1 , wherein

X is a bond or a group N—R 4 ;

R 1 is hydrogen or methyl;

R 2 is hydrogen;

R 3 is hydrogen, C 1 -C 2 alkyl, C 1 -C 2 alkoxy ;

R 4 is hydrogen, methyl, ethyl, n-propyl, isopropyl or cyclopropylmethyl;

R 5 is hydrogen, methyl or methoxy;

R 6 is hydrogen; and

n is 1 or 2.

18. The compound of claim 17 , wherein R 3 is methyl.

19. The compound of claim 18 , wherein R 5 is hydrogen.

20. The compound of claim 19 , wherein R 4 is hydrogen.

21. The compound of claim 20 , wherein R 1 is hydrogen.

22. The compound of claim 21 , wherein X is a group N—R 4 .

23. The compound of claim 22 , wherein n is 1.

24. The compound of claim 23 , wherein the OCHF 2 -radical in formula I is located on the benzene ring in the ortho-position with respect to X.

25. The compound of claim 23 , wherein the OCHF 2 -radical in formula I is located on the benzene ring in the meta-position with respect to X.

26. The compound of claim 23 , wherein the OCHF 2 -radical in formula I is located on the benzene ring in the para-position with respect to X.

27. A pharmaceutical composition comprising at least one compound of claim 1 , optionally together with at least one physiologically acceptable carrier or auxiliary substance.

28. A non-prophylactic method for treating acute or chronic signs, symptoms and/or malfunctions of a disorder selected from diseases of the central nervous system or obesity, said method comprising administering an effective amount of at least one compound of claim 1 to a subject in need thereof, wherein said disease of the central nervous system is a cognitive dysfunction associated with Alzheimer's Disease or schizophrenia.