The present invention relates to compounds of formula wherein R1 is hydrogen, halogen, cyano, lower alkyl, lower alkyl substituted by halogen, lower alkoxy, lower alkoxy substituted by halogen or C(O)NH2, or is phenyl optionally substituted by halogen, cyano or lower alkoxy substituted by halogen, or is 2,2-difluorobenzo[d][1,3]dioxol-5-yl, or is 6-(trifluoromethyl)pyrazin-2-yl or 5-(trifluoromethyl)pyrazin-2-yl or is 6-(trifluoromethyl)pyrimidin-4-yl, or is 6-(trifluoromethyl)pyridin-3-yl, or is 5-cyanopyrazin-2-yl or is 2-(trifluoromethyl)pyrimidin-4-yl； n is 1 or 2 R2 is halogen, lower alkyl or cyano and R3 is hydrogen, or R2 is hydrogen and R3 is halogen, lower alkyl or cyano； X is a bond, -NR’-, -CH2NH- or -CHR’-； R’ is hydrogen or lower alkyl； Z is a bond, -CH2- or -O-； Ar is phenyl or is heteroaryl, selected from the group consisting of 1H-indazole-3yl, pyridine-2-yl, pyridine-3-yl, pyridine-4-yl, pyrimidine-5-yl, 1H-pyrazole-3-yl, 1H-pyrazole-4-yl or 1H-pyrazole-5-yl； or to a pharmaceutically suitable acid addition salt thereof, which may be used for the treatment of depression, anxiety disorders, bipolar disorder, attention deficit hyperactivity disorder (ADHD), stress-related disorders, psychotic disorders, schizophrenia, neurological diseases, Parkinson’s disease, neurodegenerative disorders, Alzheimer’s disease, epilepsy, migraine, hypertension, substance abuse, metabolic disorders, eating disorders, diabetes, diabetic complications, obesity, dyslipidemia, disorders of energy consumption and assimilation, disorders and malfunction of body temperature homeostasis, disorders of sleep and circadian rhythm, and cardiovascular disorders.本發明係關於下式化合物其中R1 係氫、鹵素、氰基、低碳數烷基、經鹵素取代之低碳數烷基、低碳數烷氧基、經鹵素取代之低碳數烷氧基或C(O)NH2，或係視情況經鹵素、氰基或經鹵素取代之低碳數烷氧基取代之苯基，或係2,2-二氟苯并[d][1,3]二氧雜環戊烯-5-基，或係6-(三氟甲基)吡嗪-2-基或5-(三氟甲基)吡嗪-2-基或係6-(三氟甲基)嘧啶-4-基，或係6-(三氟甲基)吡啶-3-基，或係5-氰基吡嗪-2-基或係2-(三氟甲基)嘧啶-4-基；n為1或2 R2 係鹵素、低碳數烷基或氰基且R3係氫，或R2 係氫且R3係鹵素、低碳數烷基或氰基；X 係鍵結、-NR'-、-CH2NH-或-CHR'-；R' 係氫或低碳數烷基；Z
