The invention relates to compounds of the general formula I where R 1 is hydrogen, halogen, lower alkyl, lower alkoxy, lower alkoxy, substituted with halogen or cyano； R 1 is hydrogen, lower alkyl or lower alkyl substituted with halogen； R is phenyl, benzo [1,3] dioxolyl, 2,3-dihydrobenzofuran-5-yl or 5- and 6-membered heteroaryl, where phenyl and 5- and 6-membered heteroaryl groups may be substituted with one or more substituents selected from cyano, nitro, amino and lower dialkylamino, lower alkylsulfonyl, lower alkoxy, lower alkoxy substituted with halogen, halogen, lower alkyl, lower alkyl substituted with halogen, or lower alkyl substituted with hydroxyl； X represents —CH (lower alkyl) -, —CH—, —CHCH— or —CH (lower alkyl) CH—； R represents hydrogen or lower alkyl； n represents 1 or 2； or pharmaceutically acceptable acid addition salts, racemic mixtures, or their corresponding enantiomers and / or their optical isomers. The compounds can be used to treat schizophrenia, obsessive-compulsive personality disorder, major depression, bipolar disorders, anxiety disorders, normal aging, epilepsy, retinal degeneration, traumatic brain injury, spinal cord damage, post-traumatic stress, panic disorder, Parkinson's disease, dementia, Alzheimer's disease, mild cognitive impairment caused by chemotherapy for cognitive dysfunction (“chemical brain”), Down syndrome, autism spectrum disorders, sweat and hearing loss, tinnitus, spinocerebellar ataxia, amyotrophic lateral sclerosis, multiple sclerosis, diseaseИзобретение относится к соединениям общей формулы Iгде Rпредставляет собой водород, галоген, низший алкил, низший алкокси, низший алкокси, замещенный галогеном или циано； Rпредставляет собой водород, низший алкил или низший алкил, замещенный галогеном； Rпредставляет собой фенил, бензо[1,3]диоксолил, 2,3-дигидробензофуран-5-ил или 5- и 6-членный гетероарил, где фенил и 5- и 6-членные гетероарильные группы могут быть замещены одним или более заместителями, выбранными из циано,
