The present invention relates to compounds of formula I
wherein one of R
1
and R
2
is hydrogen and the other one is
and wherein A and R
1
to R
4
are as defined in the description and claims, and pharmaceutically acceptable salts thereof. The compounds are useful for the treatment and/or prevention of diseases which are associated with the modulation of H3 receptors.
本发明涉及一种具有以下结构的化合物,其中R1和R2中的一个是
氢,另一个是,A和R1至R4如描述和声明中所定义,并且其药用盐。这些化合物可用于治疗和/或预防与H3受体调节相关的疾病。