[Top Row] SKF-38393 (partial agonist) and SKF-82958 (full agonist) are phenylbenzazepines. SKF-89626 had higher intrinsic activity than SKF-38393, but lacked BBB permeability. CY208243 is a high D1 intrinsic activity ergoline. [Bottom row] Four full D1 agonists from four different chemotypes: A-77636, A-86829 (the active compound of the diacetyl prodrug ABT-431), dihydrexidine (DAR-0100A), and dinapsoline. The most pharmacologically active isomer is shown in all cases, although these compounds are sometimes used as racemates.