A compound having the following formula or a pharmaceutically acceptable salt thereof: where: R″ is a hydrogen atom or a (C1-C4)alkyl group; n′ is 1 or 2; n is 1, 2, or 3; R independently represents a hydrogen atom, a halogen atom, or a group selected from a (C1-C3)alkyl group, a —CN group, a hydroxyl group, a —NR1R2 group, a —COOR1 group, a (C1-C3)fluoroalkyl group, a —NO2 group, a (C1-C3)fluoroalkoxy, and a (C1-C4)alkoxy group; R′ is a hydrogen atom, a halogen atom, or a group selected from a (C1-C3)alkyl group, a —COOR1 group, a —NO2 group, a —NR1R2 group, a (C1-C4)alkoxy group, and a CN group; R1 and R2 are a hydrogen atom or a (C1-C3)alkyl group; with the proviso that when R and R′ are not simultaneously a hydrogen atom: when n is 1, R is not a methyl group in an ortho or para position with respect to N, when R′ is a hydrogen atom, R is not a bromine atom or a chlorine atom, and when R is a hydrogen atom, R is not a methyl or ethyl group, a —COOH group, a —COOC2H5 group, or a bromine atom that is in an ortho position of the bond linked to NR″.