Azetidine amide derivatives as orexin receptor antagonists

1. A compound of formula (I)

wherein the carbon atom at position 2 of the azetidine ring is in absolute (S)-configuration;

ring A 3 represents a meta di-substituted 5-membered heteroarylene ring containing one, two or three heteroatoms; wherein at least one of said heteroatoms is nitrogen, and the remaining is/are independently selected from oxygen, sulfur and nitrogen;

ring A 2 represents phenyl or 6-membered heteroaryl; wherein said phenyl or 6-membered heteroaryl is independently unsubstituted, or mono-, di-, or tri-substituted; wherein the substituents are independently selected from (C 1-4 )alkyl, (C 1-4 )alkoxy, halogen, (C 1-3 )fluoroalkyl, (C 1-3 )fluoroalkoxy, and (C 3-6 )cycloalkyl-oxy-;

ring A 1 represents phenyl or 5- or 6-membered heteroaryl, wherein said phenyl or 5- or 6-membered heteroaryl independently is mono-, di-, or tri-substituted; wherein

one of said substituents is attached in ortho-position to the point of attachment of A 1 to the rest of the molecule; wherein said substituent is phenyl or 5- or 6-membered heteroaryl; wherein said phenyl or 5- or 6-membered heteroaryl substituent is independently unsubstituted, mono-, di-, or tri-substituted, wherein the substituents are independently selected from (C 1-4 )alkyl, (C 1-4 )alkoxy, halogen, (C 1-3 )fluoroalkyl, and (C 1-3 )fluoroalkoxy;

and the other of said substituents, if present, is/are independently selected from (C 1-4 )alkyl, (C 1-4 )alkoxy, halogen, (C 1-3 )fluoroalkyl, (C 1-3 )fluoroalkoxy and dimethylamino;

or a pharmaceutically acceptable salt thereof.

2. A compound according to claim 1 ; wherein the ring A 3 is a meta di-substituted 5-membered heteroarylene ring selected from oxadiazol-diyl, triazol-diyl, isoxazol-diyl, oxazol-diyl, thiazol-diyl, pyrazol-diyl, imidazol-diyl, isothiazol-diyl, and thiadiazol-diyl;

or a pharmaceutically acceptable salt thereof.

3. A compound according to claim 1 ; wherein the ring A 3 represents

wherein the asterisks indicate the bond that is linked to the azetidin-2-yl moiety of the molecule;

or a pharmaceutically acceptable salt thereof.

4. A compound according to claim 1 ; wherein ring A 2 represents

phenyl which is mono- or di-substituted; wherein the substituents are independently selected from (C 1-4 )alkyl, (C 1-4 )alkoxy, halogen, and (C 1-3 )fluoroalkoxy; or

6-membered heteroaryl containing one or two ring nitrogen atoms; wherein said heteroaryl is mono-substituted; wherein the substituent is selected from (C 1-4 )alkoxy and (C 3-6 )cycloalkyl-oxy-;

or a pharmaceutically acceptable salt thereof.

5. A compound according to claim 1 ; wherein the group A 3 -A 2 represents a group independently selected from the following groups A, B and C:

A: [1,2,4]oxadiazol-3,5-diyl groups selected from the groups:

A.1

A.2

A.3

B: [1,2,4]oxadiazol-3,5-diyl groups selected from the groups:

B.1

B.2

B.3

C: [1,2,4]triazol-3,5-diyl groups selected from the groups:

C.1

C.2

C.3

or a pharmaceutically acceptable salt thereof.

6. A compound according to claim 1 ; wherein one or both of the following characteristics are present:

in case ring A 1 represents a 5-membered heteroaryl group, such group is an oxazolyl or a thiazolyl group; and/or

in case ring A 1 represents a 6-membered heteroaryl group, such group is a pyridinyl, a pyrazinyl, or a pyrimidinyl group;

or a pharmaceutically acceptable salt thereof.

7. A compound according to claim 1 ; wherein one or more of the following characteristics are present:

in case said ortho substituent of ring A 1 represents a 5-membered heteroaryl group, such group is an unsubstituted [1,2,3]triazol-2-yl] group; and/or

in case said ortho substituent of ring A 1 represents a 6-membered heteroaryl group, such group is an unsubstituted pyrimidin-2-yl group; and/or

in case said ortho substituent of ring A 1 represents a phenyl group, such group is an unsubstituted or mono-substituted phenyl group wherein the substituent is selected from (C 1-4 )alkyl, (C 1-4 )alkoxy, and halogen;

or a pharmaceutically acceptable salt thereof.

8. A compound according to claim 1 ; wherein ring A 1 represents a group

wherein

(R x ) m represents one or two substituents independently selected from (C 1-4 )alkyl, (C 1-4 )alkoxy, halogen, (C 1-3 )fluoroalkyl, and (C 1-3 )fluoroalkoxy; and

Ar 4 represents unsubstituted or mono-substituted phenyl wherein the substituent is selected from the group consisting of (C 1-4 )alkyl, (C 1-4 )alkoxy, and halogen; unsubstituted [1,2,3]triazol-2-yl; unsubstituted pyrazol-1-yl; unsubstituted pyridin-2-yl; or unsubstituted pyrimidin-2-yl;

or a pharmaceutically acceptable salt thereof.

9. A compound according to claim 1 ; wherein the ring A 1 represents a group selected from the following groups A and B:

A: substituted phenyl groups selected from the groups:

A.1

A.2

A.3

B: substituted 5-membered heteroaryl groups selected from the groups:

B.1

B.2

or a pharmaceutically acceptable salt thereof.

10. A compound according to claim 1 selected from:

(5-Methyl-2-[1,2,3]triazol-2-yl-phenyl)-[(S)-2-(3-o-tolyl-[1,2,4]oxadiazol-5-yl)-azetidin-1-yl]-methanone;

{(S)-2-[3-(3-Fluoro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2[3-(2-Methoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2[3-(3-Methoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[3-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[3-(2-Ethoxy-3-fluoro-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[3-(2,5-Dimethyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(5-Methyl-2-[1,2,3]triazol-2-yl-phenyl)-[(S)-2-(3-m-tolyl-[1,2,4]oxadiazol-5-yl)-azetidin-1-yl]-methanone;

{(S)-2-[3-(2-Chloro-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(5-Methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

{(S)-2-[3-(3-Fluoro-2-methoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2[3-(3-Fluoro-2-methoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4,5-Dimethyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[3-(3-fluoro-2-methoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

(4,5-Dimethyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

{(S)-2-[3-(3-Fluoro-2-methoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4,5-Dimethyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[3-(3-fluoro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

{(S)-2-[3-(3-Fluoro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4-Fluoro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

{(S)-2-[3-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(4-fluoro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4-Fluoro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[3-(3-fluoro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

{(S)-2[3-(3-Fluoro-2-methoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(4-fluoro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(5-Methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

{(S)-2-[3-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[3-(3-Fluoro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[3-(2-Ethoxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4,5-Dimethyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[3-(2-ethoxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

{(S)-2-[3-(2-Ethoxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(4-fluoro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[3-(2-Ethoxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4-Methyl-biphenyl-2-yl)-{(S)-2-[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

(2-Methyl-5-phenyl-thiazol-4-yl)-{(S)-2-[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

(2-Dimethylamino-5-phenyl-thiazol-4-yl)-{(S)-2-[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

Biphenyl-2-yl-{(S)-2-[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

{(S)-2-[3-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(4-methyl-biphenyl-2-yl)-methanone;

{(S)-2-[3-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(2-dimethylamino-5-phenyl-thiazol-4-yl)-methanone;

{(S)-2-[3-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(4,5-dimethyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

Biphenyl-2-yl-{(S)-2-[3-(3-chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

(4-Chloro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[3-(3-chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

(4-Chloro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

{(S)-2-[3-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(4-chloro-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4-Chloro-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

{(S)-2-[3-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4-Methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

{(S)-2-[3-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-chloro-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(5-Chloro-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

{(S)-2-[3-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-(5-chloro-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(5-Chloro-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[3-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-5-yl]-azetidin-1-yl}-methanone;

(5-Methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-methanone;

(4,5-Dimethyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-methanone;

(5-Methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-methanone;

{(S)-2-[5-(3-Fluoro-2-methoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(5-methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4,5-Dimethyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(3-fluoro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-methanone;

{(S)-2-[5-(2-Ethoxy-pyridin-3-yl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4,5-Dimethyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-ethoxy-pyridin-3-yl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-methanone;

{(S)-2-[5-(2-Ethoxy-pyridin-3-yl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(5-methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Fluoro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4-Chloro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-methanone;

(5-Chloro-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-methanone;

(4-Chloro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(3-fluoro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-methanone;

{(S)-2-[5-(2-Ethoxy-pyridin-3-yl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4-Chloro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-ethoxy-pyridin-3-yl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-methanone;

(5-Chloro-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-ethoxy-pyridin-3-yl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-methanone;

{(S)-2-[5-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(4,5-dimethyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(5-methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4-Chloro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(3-chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-methanone;

{(S)-2-[5-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(5-chloro-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(4-chloro-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(2-[1,2,3]triazol-2-yl-4-trifluoromethyl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(5-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(4,5-dimethyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(5-methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(4-chloro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(5-chloro-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(4-methyl-biphenyl-2-yl)-methanone;

{(S)-2-[5-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(5-methoxy-4-methyl-2-pyrimidin-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(5-methyl-2-pyrimidin-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

{(S)-2-[5-(3-Chloro-2-methoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-azetidin-1-yl}-(4-chloro-2-[1,2,3]triazol-2-yl-phenyl)-methanone;

(4-Methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-4H-[1,2,4]triazol-3-yl]-azetidin-1-yl}-methanone;

(4,5-Dimethyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-4H-[1,2,4]triazol-3-yl]-azetidin-1-yl}-methanone;

(5-Methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-4H-[1,2,4]triazol-3-yl]-azetidin-1-yl}-methanone;

(5-Chloro-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-4H-[1,2,4]triazol-3-yl]-azetidin-1-yl}-methanone;

(4-Chloro-5-methoxy-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-4H-[1,2,4]triazol-3-yl]-azetidin-1-yl}-methanone;

(4-Chloro-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-4H-[1,2,4]triazol-3-yl]-azetidin-1-yl}-methanone;

(2-[1,2,3]Triazol-2-yl-4-trifluoromethyl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-4H-[1,2,4]triazol-3-yl]-azetidin-1-yl}-methanone; and

(4-Methyl-biphenyl-2-yl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-4H-[1,2,4]triazol-3-yl]-azetidin-1-yl}-methanone;

or a pharmaceutically acceptable salt thereof.

11. A pharmaceutical composition comprising, as active principle, one or more compounds according to claim 1 , or a pharmaceutically acceptable salt thereof, and at least one therapeutically inert excipient.

12. A method of treatment of sleep disorders, anxiety disorders, addiction disorders, cognitive dysfunctions, mood disorders, and appetite disorders; comprising administering to a patient an effective amount of a compound as defined in claim 1 , or a pharmaceutically acceptable salt thereof.