Preparation of podate ligand [1,2,4,5-tetrakis(pyrazol-1-ylmethyl-3-carboxylic acid)benzene] and its metal complexes for use as diagnostic imaging agents

The invention provides a novel podate ligand H4L[1,2,4,5-tetrakis(pyrazol-1-ylmethyl-3-carboxylic acid)benzene] and to complexes comprising the ligand and a metal ion. Pharmaceutical compositions and methods of making and using the metal-podate complex for enhancement of diagnostic imaging are also described.