| abstract |
The present invention relates to compounds of formula wherein Ar1, Ar2 and Ar3 are independently from each other unsubstituted or substituted aryl or heteroaryl; R1, R2 and R3 are independently from each other hydroxy, halogen, lower alkyl, lower alkyl substituted by halogen, lower alkoxy, lower alkoxy substituted by halogen, cyano, 3-hydroxy-oxetan-3-yl, SO2-lower alkyl or di-lower alkyl amino; R4/R5 are independently from each other hydrogen, lower alkyl, lower alkyl substituted by halogen, lower alkyl substituted by hydroxy, -(CH2)o-O-lower alkyl, -(CH2)o-N-(lower alkyl)2, (CH2)p-cycloalkyl, (CH2)p-aryl, which aryl ring may be substituted by halogen, or R4 and R5 may form together with the N-atom to which they are attached a heterocyclic ring, optionally with further ring-heteroatoms selected from N, O or S; R6 is hydrogen or lower alkyl; R7 is hydrogen or lower alkyl; R8 is hydrogen or cyano; n is 0,1, 2 or 3; o is 1, 2 or 3; p is 0, 1 or 2; or to pharmaceutically suitable acid addition salts, optically pure enantiomers, racemates or diastereomeric mixtures thereof. It has been found that the compounds of formula I are orexin receptor antagonists and the related compounds may be useful in the treatment of disorders, in which orexin pathways are involved like sleep disorders. |