| abstract |
A pyrimidone derivative represented by formula (I) or a salt thereof, or a solvate thereof or a hydrate thereof having inhibitory activity against tau protein kinase 1:wherein R1 represents a C1-C12 alkyl group which may be substituted; R represents, for example, a group represented by the following formula (II):wherein R2 and R3 independently represent a hydrogen atom or a C1-C8 alkyl group; R4 represents a benzene ring which may be substituted, a naphthalene ring which may be substituted, an indan ring which may be substituted, a tetrahydronaphthalene ring which may be substituted, or an optionally substituted heterocyclic ring having 1 to 4 hetero atoms selected from the group consisting of oxygen atom, sulfur atom and nitrogen atom, and having 5 to 10 ring-constituting atoms in total. |