| abstract |
The pyrimidone derivative represented by the formula (I), or a salt thereof, or a solvate thereof, or a hydrate thereof having inhibitory activity of tau protein kinase 1, wherein R represents a C-C1-6 alkyl group which may be substituted; R represents, for example, a group represented by the formula (II), wherein R and R independently represent a hydrogen atom or a C 1-6 alkyl group; R represents a benzene ring which may be substituted, a naphthalene ring which may be substituted, an indane ring which may be substituted, a tetrahydronaphthalene ring which may be substituted, or an optionally substituted heterocyclic ring containing from 1 to 4 heteroatoms selected from the group including an oxygen atom, a sulfur atom and a nitrogen atom, and containing only 5 to 10 atoms making up the ring. |