Synthesis and Evaluation in Monkey of [<sup>18</sup>F]4-Fluoro-<i>N</i>-methyl-<i>N</i>-(4-(6-(methylamino)pyrimidin-4-yl)thiazol-2-yl)benzamide ([<sup>18</sup>F]FIMX): A Promising Radioligand for PET Imaging of Brain Metabotropic Glutamate Receptor 1 (mGluR1)
作者:Rong Xu、Paolo Zanotti-Fregonara、Sami S. Zoghbi、Robert L. Gladding、Alicia E. Woock、Robert B. Innis、Victor W Pike
DOI:10.1021/jm4012017
日期:2013.11.27
We sought to develop a PET radioligand that would be useful for imaging human brain metabotropic subtype 1 receptors (mGluR1) in neuropsychiatric disorders and in drug development. 4-Fluoro-N-methyl-N-(4-(6(methylamino)pyrimidin-4-yOthiazol-2-ylbenzamide (FIMX, 11) was identified as having favorable properties for development as a PET radioligand. We developed a method for preparing [F-18]11 in useful radiochemical yield and in high specific activity from [18F]fluoride ion and an N-Boc-protected (phenyl)aryliodonium salt precursor (15). In baseline experiments in rhesus monkey, [F-18 ]11 gave high brain radioactivity uptake, reflecting the expected distribution of mGluR1 with notably high uptake in cerebellum, which became 47% lower by 120 min after radioligand injection. Pharmacological challenges demonstrated that a very high proportion of the radioactivity in monkey brain was bound specifically and reversibly to mGluRl. [F-18]11 is concluded to be an effective PET radioligand for imaging mGluR1 in monkey brain and therefore merits further evaluation in human subjects.