The present invention relates to a compounds of formula (I) wherein R1 is hydrogen or lower alkyl R2 is hydrogen, lower alkyl, lower alkyl substituted by halogen or is halogen or CN, and may be independently from each other if o is 2 Ar1 is aryl or heteroaryl Ar2 is aryl or heteroaryl R/R" are independently from each other hydrogen, lower alkyl, lower alkoxy, halogen, C(O)- lower alkyl, cyano or lower alkyl substituted by halogen m is 0, 1, or 2 when n is 0 or m is 0 or 1 when n is 1 n is 0 or 1 o is 1 or 2 or to pharmaceutically active salts, racemic mixtures, enantiomers, optical isomers or to tautomeric forms thereof. It has been found that the present compounds are high potential NK-3 receptor antagonists for the treatment of depression, pain, psychosis, Parkinsons disease, schizophrenia, anxiety and attention deficit hyperactivity disorder (ADHD).
