Iododestannylation: An Improved Synthesis of Iodoproxyfan, a Specific Radioligand of the Histamine H3 Receptor

Article abstract of DOI:10.1002/(SICI)1099-1344(199707)39:7<601::AID-JLCR2>3.0.CO;2-V

<125I>Iodoproxyfan, a specific radioligand of histamine H₃ receptors, was synthesized in 60percent yield under very mild conditions from a tributylstannyl precursor.The arylstannane, which was obtained in a palladium-catalyzed reaction of arylbromide and hexabutylditin, smoothly underwent radioiodination with <125I>sodium iodide and chloramine-T to give tritylated <125I>iodoproxyfan.Final detritylation was achieved with formic acid 90percent at room temperature.Compared to the original copper(I)-mediated halogen exchange this procedure has major advantages in terms of cost and ease of use. - Key Words: Iodine-125; iododestannylation; <125I>iodoproxyfan; histamine H₃ receptor antagonist.