| abstract |
A compound represented by the formula: n n n (wherein, R 1 and R 2 are the same or different and each represents a hydrogen atom, hydrocarbon group or heterocyclic group, or R 1 and R 2 may form, together with the adjacent carbon atom, a 3-8 membered iso- or heterocyclic group, R 3 represents a cyclic group, a hydroxy group, a mercapto group that may have oxo, or an amino group, R 4 represents a hydrogen atom, a hydrocarbon group, a hydroxy group, a mercapto group which may have oxo, or an amino group, or R 2 and R 4 may link together to form a double bond, X represents a bond or a linear hydrocarbon group, W represents an oxygen atom or a sulfur atom, ring B represents a 5-8 membered nitrogen-containing heterocyclic group, ring C represents a benzene ring, and --- represents a single bond or a double bond), or a salt or a prodrug thereof that has excellent neurodegenerative inhibitory activity and brain penetrability, and is useful as an agent for preventing/treating neurodegenerative diseases. |