Disubstituted piperazines of the formula: ##STR1## in which: n is 1 or 2, X is oxygen and Y is sulfur or sulfonyl or X and Y are both sulfur or sulfonyl, and Het is a 5- or 6-membered heterocyclic radical having from 1 to 3 hetero atoms inclusive selected from nitrogen and sulfur and optionally substituted by one or more alkyl each having from 1 to 5 carbon atoms inclusive. These compounds may be used as medicines, especially in the treatment of central nervous system disorders and Parkinson's disease.
