Antimony(III) complexes with 2-amino-4,6-dimethoxypyrimidines: Synthesis, characterization and biological evaluation

• Novel pyrimidine compound bearing disulfide bridge is synthesized and characterized by X-ray diffraction.
• A dinuclear Sb(III) complex containing pyrimidine ligand bearing disulfide bridge is newly synthesized.
• The complex (3) shows good GR inhibitory activity and good antileishmanial activity agains L. tropica promosigotes.
• The antimony (III) complexes show stronger biological activity compared with the ligands.

Novel pyrimidine compound bearing disulfide bridge, 5,5′-disulfanediylbis(2-amino-4,6-dimetoxypyrimidine) (3) was synthesized by reduction of 2-amino-4,6-dimethoxy-5-thiocyanatopyrimidine for the first time, and its structure was confirmed by X-ray crystallographic analysis. Novel binuclear antimony(III) compound of (3), {Sb[5,5′-disulfanediylbis(2-amino-4,6-dimetoxypyrimidine)]Cl3}2 (4) and mononuclear antimony(III) compounds, SbL2Cl3, [L: 2-amino-5-thiol-4,6-dimethoxy pyrimidine (2) and 2-amino-5-(1H-tetrazol-5-ylthio)-4,6-dimethoxypyrimidine (6)] were synthesized and characterized with the help of elemental analysis, molecular conductivity, FT-IR, 1H-NMR and LC–MS techniques. The geometrical structures optimized by a DFT/B3LYP/LANL2DZ method of the compounds, indicated that monomeric compounds have square pyramidal shape. Both antileishmanial activity against Leishmania tropica promastigote and glutathione reductase inhibitory activity were determined in vitro. The results showed that (3) has the best biological activity.

Figure optionsDownload as PowerPoint slide