Piperidine and piperazine derivatives

1. A compound of general formula (I)

in which:

R 1 represents a phenyl group that is substituted by one, two or three substituents selected from the group consisting of (1-2C)alkylenedioxy, a halogen atom, a hydroxyl group, a cyano group, a (1-4C) alkyl group, a (3-6C)cycloalkyl group, a halo(1-4C) alkyl group, a (1-4C)alkoxy group, and a halo(1-4C)alkoxy group;

m is 2, 3, 4, or 5;

X is CH or N;

n is 1, 2, 3, 4 or 5, provided that when X is N, n is 2, 3, 4 or 5;

Y is O or NR 2 or S;

R 2 is hydrogen, (1-4C)alkyl or phenyl(1-4C)alkyl, or is as defined for R 3 ; and

R 3 represents indan-1-yl, indan-2-yl, 1,2,3,4-tetrahydronaphth-1-yl, or 1,2,3,4-tetrahydronaphth-2-yl, each of which may bear a hydroxyl substituent on a non-aromatic carbon atom; a (3-6C) cycloalkyl group; or a phenyl group that is unsubstituted or substituted by one, two, or three substituents selected from the group consisting of (1-2C)alkylenedioxy, a halogen atom, a hydroxyl group, a (1-4C) alkyl group, a (3-6C)cycloalkyl group, a cyano group; a phenyl group, an imidazolyl group, a halo(1-4C) alkyl group, a (1-4C)alkoxy group, and a halo(1-4C)alkoxy group;

or a pharmaceutically acceptable salt thereof.

2. A compound as recited in claim 1 , in which R 1 represents benzo[1,3]dioxol-5-yl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 3,4-difluorophenyl, 3-chlorophenyl, 3-methylphenyl, 2-trifluoromethylphenyl, 3-trifluoromethylphenyl, 4-trifluoromethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 4-isopropoxyphenyl, 3,4-dimethoxyphenyl, 2,3,4-trimethoxyphenyl, 3,4,5-trimethoxyphenyl, 2-fluoro-3,4-dimethoxyphenyl, 3-chloro-4-methoxyphenyl, 4-chloro-3-methoxyphenyl, 2-trifluoromethoxyphenyl, 4-trifluoromethoxyphenyl, or 3-trifluoromethoxyphenyl.

3. A compound as recited in claim 1 , in which R 1 represents benzo[1,3]dioxol-5-yl, 2-fluorophenyl, 3,4-difluorophenyl, 2-trifluoromethylphenyl, 3-trifluoromethylphenyl, 4-trifluoromethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 3,4-dimethoxyphenyl or 2-trifluoromethoxyphenyl.

4. A compound as recited in claim 1 , in which R 1 represents 3,4-dimethoxyphenyl, 3,4,5-trimethoxyphenyl, 4-methoxyphenyl, 4-isopropoxyphenyl, or 4-trifluoromethoxyphenyl.

5. A compound as recited in any of claims 1 to 4 , in which either m or n is 2, or both m and n are 2.

6. A compound as recited in any of claims 1 to 4 , in which Y is O or NH.

7. A compound as recited in claim 5 , in which Y is O or NH.

8. A compound as recited in claims 1 to 4 , in which R 3 represents phenyl, benzo[1,3]dioxol-5-yl, 2-fluorophenyl, 4-fluorophenyl, 2,4-difluorophenyl, 4-trifluoromethoxyphenyl, 2-chlorophenyl, 4-chlorophenyl, 3,4-dichlorophenyl, 4-methylphenyl, 4-isopropylphenyl, 4-t-butylphenyl, 4-cyanophenyl, 2-trifluoromethylphenyl, 4-trifluoromethylphenyl, 2-methoxyphenyl, 4-methoxyphenyl, 4-biphenyl, 4-(1-imidazolyl)phenyl, 2-fluoro-4-methoxyphenyl, 3-fluoro-4-methoxyphenyl, 3-chloro-4-methoxyphenyl, 2-trifluoromethoxyphenyl or 4-trifluoromethoxyphenyl.

9. A compound as recited in claim 8 , in which either m or n is 2, or both m and n are 2.

10. A compound as recited in claim 8 , in which Y is O or NH.

11. A compound as recited in claim 9 , in which Y is O or NH.

12. A compound as recited in any one of claims 1 to 4 , in which R 3 represents phenyl, 2-fluorophenyl, 4-fluorophenyl, 2-chlorophenyl, 4-chlorophenyl, 4-methylphenyl, 4-isopropylphenyl, 4-cyanophenyl or 2-trifluoromethylphenyl.

13. A compound as recited in claim 12 , in which either morn is 2, or both m and n are 2.

14. A compound as recited in claim 12 , in which Y is O or NH.

15. A compound as recited in claim 13 , in which Y is O or NH.

16. A compound as claimed in any one of claims 1 to 4 , in which R 3 represents a 4-fluorophenyl group.

17. A compound as recited in claim 16 , in which either m or n is 2, or both m and n are 2.

18. A compound as recited in claim 16 , in which Y is O or NH.

19. A compound as recited in claim 17 , in which Y is O or NH.

20. A compound as recited in claim 1 , which is selected from:

1-(3,4-Dimethoxyphenethyl)-4-(2-(4-fluorophenoxy)ethyl)piperidine;

1-(4-(Trifluoromethyl)phenethyl)-4-(2-phenoxyethyl)piperidine;

4-(2-(2-Fluorophenoxy)ethyl)-1-(3,4-dimethoxyphenethyl)piperidine;

1-(3,4-Dimethoxyphenethyl)-4-(2-phenoxyethyl)piperazine;

1-(3-Methoxyphenethyl)-4-(2-phenoxyethyl)piperazine;

1-(4-Methoxyphenethyl)-4-(2-phenoxyethyl)piperazine;

1-(2-(Benzo[d][1,3]dioxol-5-yl)ethyl)-4-(2-phenoxyethyl)piperazine;

1-(3,4-Difluorophenethyl)-4-(2-phenoxyethyl)piperazine;

1-(3,4-Dimethoxyphenethyl)-4-(2-(4-chlorophenoxy)ethyl)piperazine;

4-(2-(4-(3,4-Dimethoxyphenethyl)piperazin-1-yl)ethyloxy)benzonitrile;

and pharmaceutically acceptable salts thereof.

21. A process for preparing a compound as recited in claim 1 ,

which comprises

a) reducing a compound of general formula (II)

with a reducing agent; or

b) for a compound of formula (I) in which X is N, reacting a compound of general formula (III)

in which each of Z 1 and Z 2 independently represents a leaving atom or group, with a compound of general formula (IV)

R 1 —(CH 2 ) m —NH 2   (IV)

or a corresponding compound in which one or two substituents on R 1 are protected; or

c) for a compound of formula (I) in which X is N, reacting a compound of general formula (V)

with a compound of general formula (VI)

Z 3 —(CH 2 ) n —Y—R 3   (VI)

in which Z 3 represents a leaving atom or group, and R 1 , m, n, Y, and R 3 are previously defined in claim 1 ;

followed by removing any protecting group and, optionally, forming a pharmaceutically acceptable salt.

22. A compound of general formula (II)

in which

R 1 represents a phenyl group that is substituted by one, two or three substituents selected from the group consisting of (1-2C)alkylenedioxy, a halogen atom, a hydroxyl group, a cyano group, a (1-4C) alkyl group, a (3-6C)cycloalkyl group, a halo(1-4C) alkyl group, a (1-4C)alkoxy group, and a halo(1-4C)alkoxy group;

m is 2, 3, 4, or 5;

X is CH or N;

n is 1, 2, 3, 4 or 5, provided that when X is N, n is 2, 3, 4 or 5;

Y is O, NR 2 , or S;

R 2 is hydrogen, (1-4C)alkyl or phenyl(1-4C)alkyl, or is as defined for R 3 ; and

R 3 represents indan-1-yl, indan-2-yl, 1,2,3,4-tetrahydronaphth-1-yl, or 1,2,3,4-tetrahydronaphth-2-yl, each of which may bear a hydroxyl substituent on a non-aromatic carbon atom; a (3-6C) cycloalkyl group; or a phenyl group that is unsubstituted or substituted by one, two, or three substituents selected from the group consisting of (1-2C)alkylenedioxy, a halogen atom, a hydroxyl group, a (1-4C) alkyl group, a (3-6C)cycloalkyl group, a cyano group; a phenyl group, an imidazolyl group, a halo(1-4C) alkyl group, a (1-4C)alkoxy group, and a halo(1-4C)alkoxy group;

or a pharmaceutically acceptable salt thereof.

23. A pharmaceutical composition, which comprises a compound as claimed in claim 1 , and a pharmaceutically acceptable diluent or carrier.

24. A compound which is 1-[2-(4-Fluorophenoxy)ethyl]-4-[3-(4-trifluoromethoxyphenyl)propyl]piperazine, or a pharmaceutically acceptable salt thereof.

25. A pharmaceutical composition, which comprises a compound which is 1-[2-(4-Fluorophenoxy)ethyl]-4-[3-(4-trifluoromethoxyphenyl)propyl]piperazine,

or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable diluent or carrier.