Adrenoceptor blocking agents. Compounds related to metoprolol

A group of compounds, structurally related to metoprolol, in which the aromatic nucleus is formally moved stepwise away from the ethanolamine side chain, has been studied as adrenergic agonists and antagonists. All the compounds were active on the adrenergic receptors and showed similar affinity for the receptor regardless of the distance between the aromatic nucleus and the ethanolamine moiety. An ethereal oxygen may be of importance for the affinity to the receptor but this oxygen may not necessarily have to be located as an OCH2 group between the aromatic ring and the ethanolamine chain of the beta-blocker molecule.