Synthesis and characterization of a novel thiopyridinone ligand for the formation of biologically active bismuth complexes

Abstract

Maltol and its derivatives such as hydroxypyridinones and thiomaltol have been shown to be able to complex to metals and have been determined to have anti-bacterial as well as other medicinal qualities. However, there has yet to be thiol-maltol or thiol derivatives of hydroxypyridinones that have been able to be synthesized. Bismuth complexes have also been shown to have anti-bacterial and anti-fungal properties. Therefore there is an opportunity to be able to form bismuth complexes using maltol or its derivatives that contain synergistic antibacterial qualities between the bismuth metal center and the maltol or maltol derived ligand. The objective of this research is to synthesize, characterize, and optimize the formation of a maltol derived thiopyridinone ligand that has the possibility of binding to a bismuth metal center. Much progress has been made towards the synthesis of the thiopyridinone ligand as the first proposed intermediate has been isolated, and the direct synthesis of the third proposed intermediate from the first has been performed and optimized resulting in high yields. The attempted synthesis of the target thiopyridinone ligand from this intermediate resulted in an impure product that requires further characterization. More work is required to obtain a high yield efficient method for the final step of the target thiopyridinone ligand.