Synthesis and pharmacological evaluation of tyramine congeners containing fused heterocyclic rings

Abstract A series of tyramine congeners carrying a fused heterocyclic ring were synthesized with the aim of combining the positive inotropic effect of the cardiac phosphodiesterase III inhibitors with the vasodilatory effect of heterocyclic dopamine receptor agonists. None of the compounds showed the desired combination of properties. 2-Ethoxycarbonyl-4-(2-aminoethyl)-7-hydroxyindole 24 elicited a marked hypotensive effect in spontaneously hypertensive rats.