The new method of preparing 1-(2-(2,4-dimethylphenylsulphanyl)pheny!)piperazine of formula (I) or its salt comprises a reaction of 2-(2,4-dimethylphenylsulphanyl)benzeneamine of formula (XI), wherein Me is methyl, with a suitable precursor of formation of piperazine ring of formula (Xll), wherein LG is a leaving group and R is hydrogen or a protective group, in a suitable organic solvent, wherein the reaction is carried out without presence of a base in a neutral or acidic environment. (Formulae (I), (XI), (XII))
