The present invention relates to a compound of formula I,I wherein HetAris a five or six membered heteroaryl group, selected fromwherein R1is hydrogen, halogen, lower alkyl, lower alkoxy or lower alkyl substituted by halogen, and may be the same or different, if two R1occur； R2is lower alkyl or a mono- or polydeutered derivative thereof, lower alkyl substituted by halogen or lower alkoxy, lower alkenyl unsubstituted or substituted by halogen, cycloalkyl or CH2-cycloalkyl unsubstituted or substituted by halogen, heterocycloalkyl or CH2-heterocycloalkyl unsubstituted or substituted by lower alkyl； R3is halogen, lower alkyl, lower alkyl substituted by halogen, lower alkoxy substituted by halogen or S(O)2-lower alkyl； n is 1, 2 or 3； if n is ＞1, then R3may be the same or different； or to a pharmaceutically active acid addition salt thereof, to a racemic mixture or to its corresponding enantiomer and/or an optical isomer and/or stereoisomer thereof. The compounds may be used for the treatment of Alzheimer’s disease, cerebral amyloid angiopathy, hereditary cerebral hemorrhage with amyloidosis, Dutch-type (HCHWA-D), multi-infarct dementia, dementia pugilistica or Down syndrome.本發明係關於式I化合物，I 其中 HetAr係5或6員雜芳基，其選自其中 R1係氫、鹵素、低碳烷基、低碳烷氧基或由鹵素取代之低碳烷基，且若出現兩個R1，則可相同或不同； R2係低碳烷基或其單氘化或多氘化衍生物， 由鹵素取代之低碳烷基，或低碳烷氧基， 未經取代或由鹵素取代之低碳烯基， 未經取代或由鹵素取代之環烷基或CH2-環烷基， 未經取代或由低碳烷基取代之雜環烷基或CH2-雜環烷基； R3係鹵素、低碳烷基、由鹵素取代之低碳烷基、由鹵素取代之低碳烷氧基，或S(O)2-低碳烷基； n 係1、2或3；若n係＞1，則R3可相同或不同； 或其醫藥活性酸加成鹽、其外消旋混合物、或其相應鏡像異構物及/或光學異構物及/或立體異構物。 該等化合物可用於治療阿茲海默氏病(Alzheimer’s disease)、腦類澱粉血管病變、荷蘭型遺傳性大腦出血伴類澱粉變性(HCHWA-D)、 多發性梗塞失智症、拳擊手型失智症或唐氏症候群(Down syndrome)。
