| abstract |
Disclosed are a compound represented by general formula (I) (wherein R1 and R2 each represents a hydrogen, a lower acyl, a lower alkoxycarbonyl or the like; R3 represents a lower alkyl, a halogenated lower alkyl, a cycloalkyl, a heterocycloalkyl, an optionally substituted aryl, an optionally substituted heteroaryl or the like; and R4 represents a cyano, a lower alkoxycarbonyl, a carboxy or the like) having a strong COMT inhibitory activity or a pharmacologically acceptable salt thereof, a pharmaceutical composition containing the compound or a salt thereof, and uses of the compound, the salt and the composition. |