Abstract: Fatty acid esters of 8-substituted 10-[4-(hydroxyalkyl)piperazino]-10,11-dihydrodibenzo[b,f]thiepins and oxepins having the formula ##SPC1##In which X is a sulfur or oxygen atom, R.sup.1 is a hydrogen, chloro, or trifluoromethyl radical, a lower alkyl radical having at most 5 carbon atoms, or a cycloalkyl radical having at least 3 and at most 8 carbon atoms, or an alkoxy or alkylthio radical the alkyl moiety of which has at most 4 carbon atoms, R.sup.2 is an alkyl radical having at least 5 and at most 17 carbon atoms, and n is 2, 3, or 4, and their salts with pharmaceutically acceptable inorganic and organic acids. The compounds have a high degree of neuroleptic activity and retain this activity for long periods after administration.