Compounds of the formulaAr--O--CH.sub.2 --CHOH--CH.sub.2 --NH--RwhereinAr is phenyl; phenyl monosubstituted or polysubstituted by halogen, cyano, acylamino (in which the acyl group has 1-7 carbon atoms), alkanoyl of 1-4 carbon atoms, alkyl (in which the chain can be interrupted by 1 or 2 oxygen atoms or by one sulfur atom and/or in which a multiple bond can be present) of a total of 1-10 carbon atoms, cycloalkyl of 3-8 carbon atoms, and/or cycloalkoxy of 3-8 carbon atoms; naphthyl; indanyl; indenyl; tetralyl; indolyl; indolyl monosubstituted or polysubstituted by alkyl, each of 1-4 carbon atoms; carbazolyl; or 1,2,3,4-tetrahydro-2-oxoquinolyl; andR is nitratoalkyl of 2-10 carbon atoms,and the physiologically acceptable acid addition salts thereof have valuable pharmacological properties, e.g., which make them useful for prophylaxis and treatment of heart problems, e.g., as .beta.-receptor blockers.