| 主权项 |
1. A compound represented by formula (I): wherein R is a methyl group or a fluoromethyl group, R1 is a fluorine atom, a methoxy group, an ethoxy group, a fluoromethyloxy group, a difluoromethyloxy group, or an oxetan-3-yloxy group, R2 is a hydrogen atom or a fluorine atom, R3 is a hydrogen atom, R4 is a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, a cyclopropyl group, a cyclobutyl group, or a 1-methylcyclobutyl group,or a pharmaceutically acceptable salt thereof. |
