Adducts of macrocyclic chelants

Abstract

Abstract There are provided polychelants and their metal chelates which are useful in diagnostic imaging and in radiotherapy and which comprise a plurality of macrocyclic chelant moieties, e.g. DOTA residues, conjugated to a polyamine backbone molecule, e.g. polylysine. To produce a site-specific polychelate, one or more of the macrocyclic chelant carrying backbone molecules may be conjugated to a site-directed macromolecule, e.g. a protein. For example, adducts of a macrocyclic chelant can be formed by the process of (a) dispersing a carboxylic macrocyclic chelant in a polar, anhydrous solvent, (b) adding a base with a pKa sufficient to remove all carboxyl protons to create an amine salt of the chelant soluble in the solvent, (c) chilling the reaction mixture to between about 5 DEG C. and 55 DEG C. above the freezing point of the solvent, and (d) adding substantial equimolar amount of chilled alkylhaloformate under anhydrous conditions so as to form a slurry containing the mixture carboxycarbonic anhydride of the chelant.

Inventors

• 👤 Paul F. Sieving
• 👤 Alan D. Watson

Bibliographic Details