Abstract: The compound having the structural formula I or a pharmaceutically acceptable salt thereof, is disclosed, as well as its use in the treatment of central nervous system diseases, in particular Parkinson's disease, Extra Pyramidal Syndrome, restless legs syndrome and attention deficit hyperactivity disorder, pharmaceutical compositions comprising it, and combinations with other agents.

Abstract: Compounds having the structural formula I or a pharmaceutically acceptable salt thereof, wherein R is R1-isoxazolyl, R1-oxadiazolyl, R1-dihydrofuranyl, R1-pyrazolyl, R1-imidazolyl, R1-pyrazinyl or R1-pyrimidinyl; R1 is 1, 2 or 3 substituents selected from H, alkyl, alkoxy and halo; Z is optionally substituted-aryl, or optionally substituted-heteroaryl; are disclosed, as well as their use in the treatment of central nervous system diseases, in particular Parkinson's disease and Extra Pyramidal Syndrome, pharmaceutical compositions comprising them, and combinations with other agents.

Abstract: Compounds having the structural formula I or a pharmaceutically acceptable salt thereof, wherein R is optionally substituted phenyl, furanyl, thienyl, pyridyl, pyridyl N-oxide, oxazolyl or pyrrolyl, or cycloalkenyl R1, R2, R3, R4 and R5 are H, alkyl or alkoxyalkyl; and Z is optionally substituted aryl or heteroaryl are disclosed. Also disclosed is the use of compounds of formula I in the treatment of central nervous system diseases, in particular Parkinson's disease, alone or in combination with other agents for treating Parkinson's disease, and pharmaceutical compositions comprising them.

Abstract: Compounds having the structural formula I or a pharmaceutically acceptable salt thereof, wherein R is R1, R2, R3, R4 and R5 are H, alkyl or alkoxyalkyl; R6 is H, alkyl, hydroxyalkyl or —CH2F; R7, R8 and R9 are H, alkyl, alkoxy, alkylthio, alkoxyalkyl, halo or —CF3; and Z is optionally substituted aryl, heteroaryl or heteroaryl-alkyl are disclosed. Also disclosed is the use of compounds of formula I in the treatment of central nervous system diseases, in particular Parkinson's disease, alone or in combination with other agents for treating Parkinson's disease, and pharmaceutical compositions comprising them.