[A search for new beta-adrenoblockaders in the series of 5-phenoxymethyl-1,2,4-oxadiazole derivatives].

: The experiments on anesthesized rats have revealed that some derivatives of (3-amino-2-hydroxypropoxy)phenomethyl-1,2,4-oxadiazole with the oxadiazole cycle at the o-position of the aromatic ring possess a significant beta-adrenoceptor blocking activity associated with alpha-adrenoceptor blocking properties. The most potent compound is 3-methyl-5-[2-(3-tret.butylamino-2-hydroxypropoxy) phenoxymethyl]-1,2,4-oxadiazole (Compound 1, prodolol) which is superior to propranolol, oxprenolol, and particularly labetalol in its beta-adrenoceptor blocking activity. The agent does not greatly differ from labetalol in its alpha-adrenoblocking activity. Proxodolol has been chosen for preclinical and clinical studies.