PREPARATION OF 3-HYDROXY-PYRIDIN-2-ONE (3,2-HOPO) SULFONATE SALTS: USEFUL INTERMEDIATES FOR THE SYNTHESIS OF 3,2-HOPO TETHERED SULFONAMIDES, SULFONYL AZIDES, AND SULFONATE ESTERS.
Chintelle James, Tai Tai Phan, Chris Cook, Hollie Jacobs, Aravamudan Gopalan.
New Mexico State University, Las Cruces, NM.
Chelators carrying the 3-hydroxypyridin-2-one (3,2-HOPO) ligand have therapeutic and diagnostic appeal because of their ability to form strong complexes with hard metal ions such as iron and gadolinium. This could allow the removal of excess of iron in people suffering from Cooley’s anemia. Other compounds could also be tied to the sulfonate salt to produce a variety of ligands such as amino acids (sarcosine) that could be used for enzymatic studies. The purpose of this study is to develop a convenient tethering methodology to prepare suitable HOPO sulfonyl intermediates that can be linked to various amines, alcohols, and amino acids to generate a variety of HOPO sulfonyl ligands. A simple route for HOPO-sulfonamides and HOPO-sulfonate + sarcosine that uses sulfonyl chloride for the key coupling step has been identified. Both the strategy and efforts to improve the efficiency of the route will be presented.