A preliminary pharmacologicalstudy of a thiophenic isoster of propranolol and relatedcompounds with a tert. butylamino or homoveratrylamino group instead of the isopropylamino group is described. The synthesis and somepharmacological properties of derivatives in which the benzene ring is replaced by a cyclopentene or cyclohexene ring are also reported. Compounds carrying the tert. butylamino moiety