The compound of the formula ##STR00001## wherein the * indicates an asymmetric carbon, is specific to alpha.sub.2B adrenergic receptors in preference over alpha.sub.2A and alpha.sub.2C adrenergic receptors, and as such has no or only minimal cardivascular and/or sedatory activity. The compound is useful as medicament in mammals, including humans, for treatment of diseases and or alleviations of conditions which are responsive to treatment by agonists of alpha.sub.2B adrenergic receptors.