Ultra-short-acting .beta.-adrenergic receptor blocking agents. 3. Ethylenediamine derivatives of (aryloxy)propanolamines having esters on the aryl function

Various ethylenediamine derivatives have been incorporated into the nitrogen substituent of certain short-acting (aryloxy)propanolamine systems that contain esters on their aryl functions. Although several of these compounds showed durations of action comparable to their prototypes, most of the nitrogen substituents significantly prolonged the duration of beta-adrenergic blockade. Similarly, while one of the compounds showed appreciable cardioselectivity in vitro, generally, little enhancement of cardioselectivity was obtained. A brief discussion of structure-activity relationships observed for the ethylenediamine derivatives is presented.