| abstract |
Disclosed is a compound represented by the formula below, which is useful as a preventive/therapeutic agent for diseases associated with melatonin activity, or a salt thereof. (In the formula, R1 represents an optionally substituted hydrocarbon group, an optionally substituted amino, an optionally substituted hydroxy or an optionally substituted heterocyclic group; R2 represents a hydrogen atom or an optionally substituted hydrocarbon group; R3 represents a hydrogen atom, a halogen atom, an optionally substituted hydrocarbon group, an optionally substituted amino, an optionally substituted hydroxy or an optionally substituted mercapto; Xa-Xe respectively represent a carbon atom or a nitrogen atom; m represents a number of 0-2; and ring A to ring C respectively represent an optionally substituted ring.) |