Solid-phase combinatorial synthesis of 5-arylalkylidene rhodanine

Rhodanine-3-acetic acid was loaded on Wang resin or Rink amide resin. Alternatively, the thiocarbonyldiimidazole-activated Wang amino acid resin or 2-chlorotrityl resin was reacted with methyl thioglycolate to yield the rhodanine moieties. It was then condensed at the C-5 active methylene with either aromatic aldehydes or aromatic ketones. 5-Arylalkylidene rhodanine was obtained upon resin cleavage.