A Novel Semisynthetic Anion Receptor: Synthesis and Ion Recognition of (1-H-pyrrol-2-yl)-4-oxo-perezone

We describe the synthesis of the novel 2-(1,5-dimethyl-4-oxo-hexyl)-3-hydroxy-5-methyl-6-pyrrolyl-1,4- benzoquinone 2 from the natural product perezone 1. The anion–guest properties of the new compound were evaluated in the presence of fluoride, chloride, bromide and iodide tetrabutylammonium salts using 1H NMR titration techniques in deuterated dichloromethane or dimethylformamide. The title compound showed interesting colorimetric behavior in the presence of inorganic salts.