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 was studied in isolated guinea pig tissues. 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 substituent, the 2-methoxy-4-substituted derivatives had enhanced potency and selectivity but the 2,3- and the 2,5-disubstitution patterns showed a loss of activity. The inconsistent changes in activity prevented any firm conclusions being made about the effect of the ether O2 and the .beta.-adrenoceptor antagonistic activity of phenoxypropanolamines.