Carbon-11 Radiolabelling of Organosulfur Compounds: 11C Synthesis of the Progesterone Receptor Agonist Tanaproget

Herein a new C-11 radiolabelling strategy for the fast and efficient synthesis of thioureas and related derivatives using the novel synthon, (CS2)-C-11, is reported. This approach has enabled the facile labelling of a potent progesterone receptor (PR) agonist, [C-11]Tanaproget, by the intramolecular reaction of the acyclic aminohydroxyl precursor with (CS2)-C-11, which has potential applications as a positron emission tomography radioligand for cancer imaging.