Naphthyridine derivative

Provided, for example, are a compound described below and the like, which have amyloid production inhibitory activity, especially BACE1 inhibitory effect and serve as therapeutic agents for diseases induced by the production, secretion and deposition of amyloid protein. A compound represented by formula (I), a pharmaceutically acceptable salt thereof, or a solvate of the compound or the salt. (In the formula, ring Z represents a substituted or unsubstituted pyridine or a substituted or unsubstituted carbon ring; ring A represents a substituted or unsubstituted carbon ring or a substituted or unsubstituted heterocyclic ring; R