Benzofuran derivatives represented by the general formula: ##STR1## in which: R represents an ethyl, n-propyl, isopropyl or n-butyl radical; R.sub.1 represents a branched-chain alkyl radical having from 4 to 7 carbon atoms of which at least one does not bear a hydrogen atom; R.sub.2 represents hydrogen, chlorine or bromine; n is 1 or 2 and pharmaceutically acceptable acid addition salts thereof. These derivatives have been found to possess calcium translocation inhibiting properties and antiadrenergic properties and can thus be used in the treatment of certain pathological syndromes of the cardiovascular system.