N-aroyl cyclic amine derivatives as orexin receptor antagonists

1. A compound of formula (I):

wherein:

X represents CH 2 ;

Y represents CO;

Het is an optionally substituted benzofuranyl;

Ar 2 represents an optionally substituted pyridyl, wherein the pyridyl is substituted by R 1 and further optional substituents;

R 1 represents hydrogen, optionally substituted(C 1-4 )alkoxy, halo, cyano, optionally substituted(C 1-6 )alkyl, or an optionally substituted phenyl;

R 3 represents hydrogen or an optionally substituted (C 1-4 )alkyl;

wherein said optionally substituted benzofuranyl, pyridyl, (C 1-4 )alkoxy, (C 1-4 )alkyl, (C 1-6 )alkyl, or phenyl is optionally substituted by halogen, hydroxy, oxo, cyano, nitro, (C 1-4 )alkyl, (C 1-4 )alkoxy, hydroxy(C 1-4 )alkyl, hydroxy(C 1-4 )alkoxy, halo(C 1-4 )alkyl, halo(C 1-4 )alkoxy, aryl(C 1-4 )alkoxy, (C 1-4 )alkylthio, hydroxyl(C 1-4 )alkyl, (C 1-4 )alkoxy(C 1-4 )alkyl, (C 3-6 )cycloalkyl(C 1-4 )alkoxy, (C 1-4 )alkanoyl, (C 1-4 )alkoxycarbonyl, (C 1-4 )alkylsulfonyl, (C 1-4 )alkylsulfonyloxy, (C 1-4 )alkylsulfonyl(C 1-4 )alkyl, arylsulfonyl, arylsulfonyloxy, arylsulfonyl(C 1-4 )alkyl, (C 1-4 )alkylsulfonamido, (C 1-4 )alkylamido, (C 1-4 )alkylsulfonamido(C 1-4 )alkyl, (C 1-4 )alkylamido(C 1-4 )alkyl, arylsulfonamido, arylcarboxamido, arylsulfonamido(C 1-4 )alkyl, arylcarboxamido(C 1-4 )alkyl, aroyl, aroyl(C 1-4 )alkyl, aryl(C 1-4 )alkanoyl, (C 1-4 )acyl, aryl, aryl(C 1-4 )alkyl, (C 1-4 )alkylamino(C 1-4 )alkyl, R a R b N(CH 2 )n-, R a R b N(CH 2 )nO—, wherein n represents an integer from 1 to 4; or a group R a R b N—, R a OCO(CH 2 ) r , R a CON(R a )(CH 2 ) r , R a R b NCO(CH 2 ) r , R a R b NSO 2 (CH 2 ) r or R a SO 2 NR b (CH 2 ) r where each of R a and R b independently represents a hydrogen atom or a (C 1-4 )alkyl group;

or a pharmaceutically acceptable salt thereof.

2. A compound according to claim 1 wherein R 1 represents optionally substituted phenyl group.

3. A compound according to claim 1 wherein Ar 2 is optionally substituted by (C 1-4 )alkyl, hydroxy(C 1-4 )alkyl, R a R b N, (C 1-4 )alkoxy, R a R b N(CH 2 )n, (C 1-4 )acyl, and (C 1-4 )alkylamido.

4. A pharmaceutical composition comprising the compound according to claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

5. A method of treating a disease or disorder where an antagonist of a human orexin receptor is required, which comprises administering to a subject in need thereof an effective amount of the compound according to claim 1 , or a pharmaceutically acceptable salt thereof, wherein said disease or disorder is selected from obesity and obesity associated with Type II diabetes.

6. A method of treating insomnia, which comprises administering to a subject in need thereof an effective amount of the compound according to claim 1 , or a pharmaceutically acceptable salt thereof.