The present invention relates to a compound of formula I wherein R1, R2, R3, R4, R9, R10, m and n are as defined herein, or to a pharmaceutically acceptable acid addition salt thereof. The present compounds are high potential NK-3 receptor antagonists for the treatment of depression, bipolar disorders, pain, psychosis, Parkinson's disease, schizophrenia, anxiety and attention deficit hyperactivity disorder (ADHD).