A rigid dopamine congener, 2,3-dihydroxy-9-amino-9,10-dihydrophenanthrene, was synthesized and tested for the ability to dilate the renal artery in dogs. The compound was found to be inactive in this assay at molar doses 1000 times greater than required for dopamine. This result is similar to isoapomorphine. The title compound was also examined for its ability to stimulate rat striatal adenylate cyclase. In concentrations of 10-100 micrometer no effect was observed. The phenanthrene also showed no ability to block dopamine-induced stimulation of adenylate cyclase.