Synthesis and characterization of some gold(I) - thiolate complexes having N-methylimidazole moiety

Abstract

Antithyroid drugs inhibit the thyroid hormone synthesis by inactivating the thyroid peroxidase and/or iodothyronine deiodinase, which are involved in iodination and deiodination reactions. Gold(I) compounds also inhibit the thyroid hormone synthesis by interacting with the selenocysteine residue of iodothyronine deiodinase. However, the chemical reactions between these two different classes of compounds have not been studied. In this paper, we describe the interaction of therapeutic gold(I) compounds with the commonly used thiourea-based antithyroid drug, methimazole. It is observed that the gold(I) phosphine complexes (R₃PAuCl, where R=Me, Et, Ph) react with methimazole only upon deprotonation to produce the corresponding gold(I)-thiolate complexes. Addition of PPh₃ to the gold(I)-thiolates produces (R₃PAuPPh₃)⁺ (R=Me or Et), indicating the possibility of ligand exchange reactions.