title: 2-Methoxyphenylethanolamines, potential beta-adrenergic blocking agents.
abstract: The effect of the introduction of a 2-methoxy substituent on the beta-adrenergic antagonistic properties of a series of 3- and 4-substituted phenylethanolamines (1) was studied. Both the series of bromo- and methyl-substituted compounds behaved similarly, indicating that electronic forces are not significant in determining beta-adrenergic antagonist activity. When compared with the corresponding phenylethanolamines without a 2-methoxy substitutent, the 2-methoxy-4-substituted derivatives (3a and 3d) had enhanced potency and selectivity but the 2,3- (3b and 3e) and the 2,5-disubstitution patterns (3c and 3f) showed a loss of activity. The inconsistent changes in activity prevented any firm conclusions being made about the effect of the ether oxygen and the beta-adrenoceptor antagonistic activity of phenoxypropanolamines.
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000138:chemical synthesis*; D000818:Animals; D004983:Ethanolamines / Q000138:chemical synthesis* / Q000494:pharmacology; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000037:antagonists & inhibitors; D013329:Structure-Activity Relationship; D014132:Trachea / Q000187:drug effects
chemical_list: D000319:Adrenergic beta-Antagonists; D004983:Ethanolamines; D007545:Isoproterenol