| abstract |
Compounds of structural formula (I) or a pharmaceutically acceptable salt thereof, wherein R is R 1, R 2, R 3, R 4 and R 5 are H, alkyl or alkoxyalkyl, R 6 is H, alkyl, hydroxyalkyl or -CH 2 F, R 7, R 8 and R 9 are H , alkyl, alkoxy, alkylthio, alkoxyalkyl, halo or -CF 3, and Z is optionally substituted aryl, heteroaryl or heteroarylalkyl is described. Furthermore, the use of compounds of formula I in the treatment of diseases of the central nervous system, in particular Parkinson's disease, alone or in combination with other agents for the treatment of Parkinson's disease, and pharmaceutical compositions comprising them is described. |