Compounds represented by the general formula (I), and xanthine oxidase inhibitors containing the same as the active ingredient: (I) wherein R1 is OR4 or the like (wherein R4 is optionally substituted C1-8 alkyl or the like); R2 is halogeno, nitro, cyano, carboxyl, or the like; R3 is hydrogen, halogeno, hydroxyl, amino, carboxyl, or the like; X is NR11, oxygen, or sulfur (wherein R11 is hydrogen or optionally substituted C1-8 alkyl); and Y and Z are each CR12 or nitrogen (wherein R12 is the same as defined for R3).