| abstract |
The present invention provides a compound which has an effect of inhibiting the production of β amyloid, especially an inhibiting effect of BACE1, and which is useful as a therapeutic or prophylactic agent for diseases induced by the production, secretion and/or deposition of β proteins. amyloids. A compound of formula (I) in which R3 is each independently alkyl optionally substituted with halogen, cyano, alkyloxy, haloalkyloxy or non-aromatic carbocyclyl, or the like; t is an integer from 0 to 3; R5 is a hydrogen or halogen atom; R6 is selected from the group consisting of a hydrogen atom, halogen, and substituted or unsubstituted alkyl, Ring B is a substituted or unsubstituted pyrazine or the like, or a pharmaceutically acceptable salt thereof. |