PROCESS FOR PURER ORGANIC METAL ION CHELATE COMPLEXES

摘要

The present invention describes a synthesis and purification of novel organic chelate metal ion (II) or (III) complexes. These processes are useful specifically for producing purer complexes for magnetic resonance imaging (MRI) contrast agents. The metal ion is first complexed, contacted with a water insoluble adsorption resin to adsorb the complex, washed with water to remove dissolved solids, contacted with a water soluble organic coupling agent and an organic diacid, acid amide, or acid ester, separating the solid resin, washing it with water, contacting the resin with polar non-aqueous organic liquid to desorb the complex followed by purification of the desorbed organic chelate metal ion complex. Similarly, preformed organic chelate metal ion complexes can be purified by contacting an aqueous slurry of organic resin followed by the described purification and separation steps.