| abstract |
Novel compounds and processes for preparation of such compounds, which are useful as dopamine receptor agonists for the treatment of various diseases of the central nervous system such as Parkinson's disease and related disorders, having the structural formulan nwhere R 2 , R 3 and R 4 are each selected from the group consisting of H, and OA; A is H orn n R 5 is selected from the group consisting of alkyl and aromatic residues; n is 2 or 3: and R, is selected from the group consisting of phenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 3-pyridyl, 4-pyridyl,n nwhere X is S, O or NH, and a pharmaceutically acceptable salt thereof with the proviso that at least one of R 2 , R 3 and R 4 is not H. |