Previously, we have demonstrated that enone prodrugs of dopaminergic catecholamines represent a new type of dopamine (DA) agonist. Trans-1-propyl-1,2,3,4,4a,5,10,10a-octahydrobenzo[g]quinoline-6,7-diol (TL-334), the active form of trans-1-propyl-2,3,4,4a,5,7,8,9,10,10a-decahydro-1H-benzo[g]quinolin-6-one (GMC-6650), in vivo showed an extremely potent dopaminergic activity. Here, we report a novel synthesis and a pharmacological evaluation of TL-334 by means of microdialysis.