Bronchodilators. 3,4,5-trihydroxyphenylethanol amines

In an attempt to further define the effect of ring substitution on the β-adrenergic activity of phenylethanol amines, a group of 3,4,5-trihydroxy-substituted N-alkylphenylethanol amines were prepared. The synthesis of these compounds and their effect on bronchodilator activity and force and rate of contraction of isolated guinea pig atria are discussed.