Diphenyl sulfide derivatives and medicines containing same as active ingredient

A diphenyl sulfide compound, or a pharmaceutically acceptable salt or hydrate thereof, represented by formula (1),

• wherein R1 represents a hydrogen atom, a halogen atom, a trifluoromethyl group, an optionally substituted alkyl group having 1 to 6 carbon atoms, an optionally substituted cycloalkyl group having 3 to 6 carbon atoms, an optionally substituted aryl group having 6 to 10 carbon atoms, an optionally substituted alkoxy group having 1 to 4 carbon atoms, an optionally substituted benzyloxy group, an optionally substituted acyl group having 1 to 4 carbon atoms, a cyano group, or a carboxyl group;
• R2 represents an optionally substituted alkyl group having 1 to 6 carbon atoms or an optionally substituted alkenyl group having 2 to 6 carbon atoms;
• X represents a methylene group which may be substituted with 1 or 2 fluorine atoms or represents an oxygen atom;
• Y represents a hydrogen atom or an optionally substituted alkyl group having 1 to 6 carbon atoms;
• and Z represents a halogen atom.