A compound represented by the Formula (I), or a salt thereof: wherein at least one of R 1 or R 2 represents an optionally substituted naphthyl group; either R 1 or R 2 represents, if not the optionally substituted naphthyl group, a hydrogen atom, an optionally substituted hydrocarbon group, or an optionally substituted monocyclic heterocyclic group; R 3 represents a hydrogen atom, an optionally substituted hydrocarbon group, or an optionally substituted heterocyclic group; X represents a -CO- group or -SO 2 - group; wherein optionally substituted means that one substituent or two or more identical or different substituents are optionally present, wherein the substituents are selected from a halogen, a C 1-6 alkyl group, a C 3-6 cycloalkyl group, a C 2-6 alkynyl group, a C 2-6 alkenyl group, a C 7-11 aralkyl group, a C 6-10 aryl group, a C 1-6 alkoxy group, a C 6-10 aryloxy group, a C 1-6 alkyl-carbonyl group, a C 6-10 aryl-carbonyl group, a C 1-6 alkyl-carbonyloxy group, C 6-10 aryl-carbonyloxy group, a carboxyl group, a C 1-6 alkoxy-carbonyl group, a C 7-11 aralkyloxycarbonyl group, a carbamoyl group, mono-, di-, or tri-halogenated -C 1-4 alkyl group, an oxo group, an amidino group, an imino group, an amino group, a mono-C 1-4 alkylamino group, a di-C 1-4 alkylamino group, a C 1-6 alkoxycarbonylamino group, a 3- to 6-membered cyclic amino group containing carbon atoms and one nitrogen atom and further containing one to three heteroatoms selected from oxygen, sulfur, and nitrogen, a C 1-3 alkylenedioxy group, a hydroxy group, a cyano group, a mercapto group, a sulfo group, a sulfino group, a phosphono group, a sulfamoyl group, a mono-C 1-6 alkylsulfamoyl group, a di-C 1-6 alkylsulfamoyl group, a C 1-6 alkylthio group, a C 6-10 arylthio group, a C 1-6 alkylsulfinyl group, a C 1-6 alkylsulfonyl group, or a C 6-10 arylsulfonyl group. at least one of R 1 or R 2 represents an optionally substituted naphthyl group; either R 1 or R 2 represents, if not the optionally substituted naphthyl group, a hydrogen atom, an optionally substituted hydrocarbon group, or an optionally substituted monocyclic heterocyclic group; R 3 represents a hydrogen atom, an optionally substituted hydrocarbon group, or an optionally substituted heterocyclic group; X represents a -CO- group or -SO 2 - group; wherein optionally substituted means that one substituent or two or more identical or different substituents are optionally present, wherein the substituents are selected from a halogen, a C 1-6 alkyl group, a C 3-6 cycloalkyl group, a C 2-6 alkynyl group, a C 2-6 alkenyl group, a C 7-11 aralkyl group, a C 6-10 aryl group, a C 1-6 alkoxy group, a C 6-10 aryloxy group, a C 1-6 alkyl-carbonyl group, a C 6-10 aryl-carbonyl group, a C 1-6 alkyl-carbonyloxy group, C 6-10 aryl-carbonyloxy group, a carboxyl group, a C 1-6 alkoxy-carbonyl group, a C 7-11 aralkyloxycarbonyl group, a carbamoyl group, mono-, di-, or tri-halogenated -C 1-4 alkyl group, an oxo group, an amidino group, an imino group, an amino group, a mono-C 1-4 alkylamino group, a di-C 1-4 alkylamino group, a C 1-6 alkoxycarbonylamino group, a 3- to 6-membered cyclic amino group containing carbon atoms and one nitrogen atom and further containing one to three heteroatoms selected from oxygen, sulfur, and nitrogen, a C 1-3 alkylenedioxy group, a hydroxy group, a cyano group, a mercapto group, a sulfo group, a sulfino group, a phosphono group, a sulfamoyl group, a mono-C 1-6 alkylsulfamoyl group, a di-C 1-6 alkylsulfamoyl group, a C 1-6 alkylthio group, a C 6-10 arylthio group, a C 1-6 alkylsulfinyl group, a C 1-6 alkylsulfonyl group, or a C 6-10 arylsulfonyl group. <EOS>