4-Substituted aryl bromides coupling with 4-methoxybenzene-1-thiol by means of copper catalysts

Synthesis of diaryl sulfides via nucleophilic coupling of the 4-substituted aryl bromides with 4-methoxybenzene-1-thiol is described. A radical-ionic mechanism of this coupling, carried out in the presence of heterogeneous copper catalysts, has been proposed. The reactivity of aryl bromides is correlated to the calculated values of electronic deficiency in position CA of the aromatic ring. The prepared compounds should be used as the leading building blocks of quinlukast higher homologues.