| Abstract: | Metal Complexes of Biologically Important Ligands. CXXVI. Palladium(II) and Platinum(II) Complexes with the Antimalarial Drug Mefloquine as Ligand The coordination sites of the antimalarial drug mefloquine (L) were studied. Reactions of the chloro bridged complexes (allyl)Pd(μ‐Cl)2Pd(allyl) and (R3P)(Cl)M(μ‐Cl)2M(Cl)(PR3) (M = Pd, Pt) with racemic mefloquine give the compounds (allyl)(Cl)Pd(L) ( 1 ), Cl2(Et3P)Pt(L) ( 2 ) and Cl2(Et3P)Pd(L) ( 3 ) with coordination of the piperidine N atom of mefloquine. In the presence of NaOMe the N,O‐chelate complexes Cl(Et3P)Pt(L–H+) ( 4 ) and Cl(R3P)Pd(L–H+) ( 5 , 6 , R = Et, nBu) were obtained. Protection of the piperidine N atom of mefloquine by protonation allows the synthesis of the complexes Cl2(Et3P)Pt(L + H+) ( 7 ) in which mefloquine is coordinated via the quinoline N atom. The structures of 2 , 3 and 4 were determined by X‐ray diffraction analysis. In the crystal of 4 pairs of enantiomers are found which are linked by two hydrogen bridges between the amine group and the chloro ligand. |
