Substituted 3,5-diphenyl-1,2,4-triazoles and their use as pharmaceutical metal chelators

Various disorders of warm-blooded animals are linked with an excess of metals, in particular trivalent metals, in the body tissues. For example, aluminum in dialysis encephalopathy and osteomalacia, as well as in Alzheimer's disease is representative. In other illnesses, in particular of man, an excess of iron occurs in the various tissues. This is designated as iron overload (formerly haemosiderosis). It occurs, e.g., after parenteral administration of iron (especially repeated blood transfusions) or after increased uptake of iron from the gastrointestinal tract. Repeated transfusions are necessary in serious anemias, especially in thalassaemia major, the severe form of -thalassaemia, but also in other anemias. Increased iron absorption from the gastrointestinal tract either takes place primarily, e.g. on account of a genetic defect (so-called haemochromatosis), or secondarily, such as after anemias in which blood transfusions are not necessary, e.g. thalassaemia intermedia, a milder form of -thalassaemia. The use is described of 3,5-diphenyl-1,2,4-triazoles of the formula I in which R-Rare as defined in the description. The compounds have useful pharmaceutical properties and are particularly active as iron chelators. They can be used for the treatment of iron overload in warm-blooded animals.