Synthesis and irreversible beta-adrenergic blockade with a bromoacetamido derivative of betaxolol

1-[4-(2-Cyclopropylmethoxyethyl)phenoxy]-3-[1-p-(bromoacetamidophe nyl) -2-methyl-2-propylamine]-2-propranol (8), which is a derivative of the beta 1-adrenergic agent betaxolol, was synthesized. Compound 8 showed less potent beta-adrenergic blocking activity than betaxolol in an in vitro test with guinea pig tracheal muscle and left atrium but retained high beta 1-selectivity. Irreversible beta-adrenoceptor antagonism of 8 was assessed by the blockade of the isoproterenol response of the guinea pig atria and by ligand binding studies with rat cerebral cortex.