[Search for new beta-adrenoblockaders among derivatives of (3-amino-2-hydroxypropoxy) phenoxymethyl isoxazole].

In experiments on anesthetized rats it was found that some derivatives of 2-(3-isopropylamino-2-hydroxypropoxy) phenoxymethyl isoxazole possess marked beta-adrenoblocking activity associated with alpha-adrenoblocking properties. The most active compound is 3-methyl-4-chloro-5-(3-isopropylamino-2-hydroxypropoxy) phenoxymethyl isoxazole hydrochloride (compound II) which by its beta-adrenoblocking activity is superior to propranolol, oxprenolol and especially labetalol. By its alpha-adrenoblocking activity the compound does not differ significantly from labetalol but it is inferior to phentolamine. Compound II has partial agonistic activity, exerts nonspecific membrane-stabilizing action and exhibits antifibrillatory and antiarrhythmic activity.