Alkylation of 2-pyrrolidinone (I) with 1,4-dibromobutane (II) in the presence of KOH and tetraethylammonium bromide gave the N-(4-bromobutyl)pyrrolidinone (III). This was condensed with 1-[4-(trifluoromethyl)-2-pyridinyl]piperazine (IV) in the presence of Na2CO3 to produce the target disubstituted piperazine, which was then converted to the corresponding fumarate salt.