The present invention relates to compounds of formula I, wherein X is —CH2— or —NH—; Y is —CH(lower alkoxy)-, —CH(lower alkyl)-, —O—, —S—, —S(O)—, —S(O)2— or —CH2—; and Ar is phenyl or naphthyl, which rings are optionally substituted by one or two substituents selected from the group consisting of halogen, lower alkoxy, lower alkyl and lower alkyl substituted by halogen; or a pharmaceutically-acceptable acid-addition salt thereof; with the proviso that, when X is —NH—, Y is —CH(lower alkyl)- or —CH2—; and the further proviso that the compound is not 2-phenethyl-1H-imidazole hydrochloride, 2-(3,4-dichloro-phenoxymethyl)-1H-imidazole hydrochloride, 2-(2-chloro-phenoxymethyl)-1H-imidazole hydrochloride, 2-(2,3-dichloro-phenoxymethyl)-1H-imidazole, benzyl-(1H-imidazol-2-yl)-amine, (4-chloro-benzyl)-(1H-imidazol-2-yl)-amine, or (2-chloro-benzyl)-(1H-imidazol-2-yl)-amine. The invention relates also to a pharmaceutically-acceptable acid-addition salt of such a compound, processes for making the compound, and a composition comprising such a compound.