We synthesized several esters of R(-)-N-alkyl-11-hydroxy-2-methoxynoraporphines, assessed their affinities at dopamine D(1) and D(2) receptors in rat forebrain tissue and quantified their effects on motor activity in normal adult male rats. Tested compounds displayed moderate to high affinities to D(2) receptors but low affinities to D(1) receptors. The most D(2)-potent (K(i)=18.9nM) and selective novel agent (>529-fold vs D(1) sites) was R(-)-2-methoxy-11-acetyloxy-N-n-propylnoraporphine (compound 4b). At moderate doses, the compound proved to have prolonged behavioral locomotor activity.