title: Improved synthesis of [11C]SA4503, [11C]MPDX and [11C]TMSX by use of [11C]methyl triflate.
abstract: Recently we have clinically used three new radioligands, [11C]SA4503, [11C]MPDX, and [11C]TMSX, for mapping sigma1, adenosine A1, and adenosine A2A receptors, respectively, in the human brain by positron emission tomography. These radioligands are synthesized by methylation of the respective demethyl precursor with [11C]methyl iodide. Here we demonstrate the improved syntheses of these compounds by use of [11C]methyl triflate, a highly reactive alternative to [11C]methyl iodide.
authors.affiliation: Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan. kawamura@pet.tmig.or.jp
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kawamura
authors.forename: Kiichi
authors.initials: K
authors.lastname: Ishiwata
mesh_terms: D002250:Carbon Radioisotopes / Q000737:chemistry; D007553:Isotope Labeling / Q000379:methods*; D008698:Mesylates / Q000737:chemistry*; D010879:Piperazines / Q000737:chemistry*; D014970:Xanthines / Q000737:chemistry*
chemical_list: C451639:1-methyl-8-dicyclopropylmethyl-1-methyl-3-propylxanthine; D002250:Carbon Radioisotopes; C405422:KF18446; D008698:Mesylates; D010879:Piperazines; D014970:Xanthines; C078465:methyl triflate; C101789:SA 4503