The present invention provides a compound of formula (I) or a salt thereof, wherein R
1
, R
2
and R
3
are independently selected from the group consisting of hydrogen atom, fluorine atom, chlorine atom, bromine atom, C
1-6
alkyl, C
1-6
alkoxy substituted with fluorine atom, and others; R
4
and R
5
are independently selected from the group consisting of hydrogen atom, fluorine atom, chlorine atom, C
1-6
alkyl, C
1-6
alkoxy substituted with fluorine atom, and others; R
6
and R
7
are independently selected from the group consisting of hydrogen atom, fluorine atom, methyl, ethyl, hydroxy group, and others; and R
8
and R
9
are independently selected from the group consisting of hydrogen atom, C
1-6
alkyl, and others, which is useful as an agent for treating or preventing various types of epilepsy including partial seizures and/or generalized seizures.
The invention provides compounds, pharmaceutical compositions and methods for the therapeutic treatment and prevention of neurodegenerative disorder and other Aβ
42
-related diseases and disorders.