| abstract |
The present invention provides compounds represented by general formula (I): (see formula I) or pharmaceutical acceptable salts thereof, wherein R1 and R2 are each hydrogen, lower acyl, lower alkoxycarbonyl or the like; R3 is halo-lower alkyl, lower acyl, halo-lower alkylcarbonyl, cycloalkylcarbonyl, optionally substituted arylcarbonyl, lower alkoxycarbonyl or the like; R4 is lower alkyl, halo-lower alkyl, cycloalkyl, lower alkoxy-lower alkyl or the like, which exhibit potent COMT inhibitory activities. The present invention also provides pharmaceutical compositions containing said compound, and uses thereof. |