The present invention relates to compounds of formulawherein R1/R2are hydrogen, lower alkyl, lower alkoxy, lower alkyl substituted by halogen, lower alkoxy substituted by halogen, cycloalkyl, OCH2-cycloalkyl or heterocycloalkyl which is optionally substituted by halogen, with the proviso that one of R1and R2is hydrogen, or R1and R2form together with the carbon atom to which they are attach a phenyl ring, which may be optionally substituted by lower alkyl； R3/R4are hydrogen, halogen or cyano； with the proviso that one of R3and R4is hydrogen； or to a pharmaceutically suitable acid addition salt thereof, to all racemic mixtures, all their corresponding enantiomers and/or optical isomers, 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.本發明係關於下式之化合物：其中R1/R2為氫、低碳烷基、低碳烷氧基、經鹵素取代之低碳烷基、經鹵素取代之低碳烷氧基、環烷基、OCH2-環烷基或視情況經鹵素取代之雜環烷基，限制條件為R1及R2中之一者為氫，或R1及R2連同其所連接之碳原子一起形成苯環，該苯環可視情況經低碳烷基取代；R3/R4為氫、鹵素或氰基；限制條件為R3及R4中之一者為氫；或其醫藥學上適合之酸加成鹽、所有外消旋混合物、所有其相應對映異構體及/或光學異構體，其可用於治療抑鬱症、焦慮症、躁鬱症、注意力不足過動症(ADHD)、壓力相關病症、精神失常、精神分裂症、神經疾病、帕金森氏病、神經退化病症、阿茲海默氏病、癲癇症、偏頭痛、高血壓、物質濫用、代謝障礙、進食障礙、糖尿病、糖尿病併發症、肥胖症、血脂異常、能量消耗及同化障礙、體溫恆定障礙及機能失調、睡眠及晝夜節律障礙及心血管病症。
