| abstract |
As a pharmaceutical composition for treating or preventing Alzheimer's disease, for example, the following pharmaceutical composition is provided. Formula (I): (In the formula, ring A is a carbocyclic group which may have a substituent or a heterocyclic group which may have a substituent, R 1 is optionally substituted lower alkyl, etc. R 2a and R 2b are each independently hydrogen, optionally substituted lower alkyl, etc. R 3a and R 3c each independently represent hydrogen, halogen, hydroxy, optionally substituted lower alkyl or the like) Or a pharmaceutically acceptable salt thereof or a solvate thereof. |