A compound indicated by formula (1) or a pharmaceutically acceptable salt thereof, having an inhibitory activity in a fractalkine-CX3CR1 pathway. [R indicates a C1-6 alkyl group having 1-3 unsubstituted groups or 1-3 substituted groups selected from a group (A) of substituted groups, a C3-8 cycloalkyl group having 1-3 unsubstituted groups or 1-3 substituted groups selected from the group (A) of substituted groups, or a C3-8 cycloalkenyl group having 1-3 unsubstituted groups or 1-3 substituted groups selected from the group (A) of substituted groups； X indicates a C1-6 alkyl group； Y and Z are the same or different and indicate a halogen atom or a C1-6 alkyl group having 1-3 unsubstituted groups or 1-3 substituted groups selected from a group (B) of substituted groups； n indicates 0 or 1, the group (A) of substituted groups comprises halogen atoms； and the group (B) of substituted groups comprises halogen atoms.]一種由式(1)代表的化合物或一其藥學上可接受的鹽，在fractalkine-CX3CR1路徑中具有抑制作用：其中R代表未被取代或具有1到3個選自取代基組A的取代基的一個C1-6烷基、未被取代或具有1到3個選自取代基組A的取代基的一個C3-8環烷基或未被取代或具有1到3個選自取代基組A的取代基的一個C3-8環烯基，X代表一個C1-6烷基，Y和Z彼此相同或不同並且各自代表一個鹵素原子或未被取代或具有1到3個選自取代基組B的取代基的一個C1-6烷基，n代表0或1，取代基組A由鹵素原子組成，並且取代基組B由鹵素原子組成。
