The present invention directs to provide a novel compound for treating and/or preventing pain, having excellent skin permeation and reduced skin irritation. The present invention provides a compound of formula (I) or a pharmaceutically acceptable salt thereof (R
1
: a methyl group or other like group, R
2
: a fluorine atom or other like group, R
3
: a methyl group or other like group, R
4
: a methyl group or other like group, R
5
: a methyl group or other like group)
本发明旨在提供一种用于治疗和/或预防疼痛的新型化合物,具有出色的皮肤渗透性和降低的皮肤刺激性。本发明提供了一种具有以下结构的化合物(I)或其药学上可接受的盐(R1:甲基基团或类似基团,R2:
氟原子或类似基团,R3:甲基基团或类似基团,R4:甲基基团或类似基团,R5:甲基基团或类似基团)。