Disclosed is a compound represented by the formula (I) below or a pharmacologically acceptable salt thereof. Also disclosed is a use of the compound or salt as a pharmaceutical product. (In the formula, Ar1 represents an imidazolyl group which may be substituted with a C1-6 alkyl group; Ar2 represents a phenyl group which may be substituted with a C1-6 alkoxy group; X1 represents a single bond; R1 and R2 respectively represent a C1-6 alkyl group or the like which may be substituted with a substituent such as a 5- to 14-membered aromatic heterocyclic group; and R3 represents a hydrogen atom or the like.)