Gas phase production of[11C]methyl iodide-d3. Synthesis and biological evaluation ofS-[N-methyl-11C]citalopram and deuterated analogues
作者:Jacob Madsen、Betina Elfving、Kim Andersen、Lars Martiny、Gitte M. Knudsen
DOI:10.1002/jlcr.820
日期:2004.5
Three 11C-labelled tracers for the serotonin reuptake site, S-[N-methyl-11C]citalopram ([11C]-4), S-[N-methyl-d3-11C]citalopram ([11C]-12), and S-[N-methyl-11C]citalopram-α,α-d2 ([11C]-13) were synthesized and the distribution of radioactivity after injection of radioligand was examined ex vivo in rats. The deuterated analogue of (S)-desmethylcitalopram, (S)-1-(4-fluorophenyl)-1-(3-methylamino-[3-d2]-propyl)-1,3-di-hydro-isobenzofuran-5-carbonitrile (11), was synthesized in a multi-step synthesis from escitalopram (4) and used as precursor in the synthesis of [11C]-13. In analogy with the reported gas phase synthesis of [11C]methyl iodide the first gas phase synthesis of [11C]Methyl iodide-d3 is reported. The 1H/2H kinetic isotope effect related to the synthesized compounds were investigated in ex vivo rat studies, where the brain regions of interest to cerebellum ratios of the tracers [11C]-4, [11C]-12 and [11C]-13 were compared. The ex vivo data indicated no significant differences in binding in any of the investigated brain regions after injection of the three tracers. Copyright © 2004 John Wiley & Sons, Ltd.
合成了三种用于血清素再摄取位点的11C标记示踪剂,S-[N-甲基-11C]西酞普兰([11C]-4)、S-[N-甲基-d3-11C]西酞普兰([11C]-12)以及S-[N-甲基-11C]西酞普兰-α,α-d2([11C]-13),并在大鼠体外检查了注射放射性配体后的放射性分布。(S)-去甲基西酞普兰的重氘类似物(S)-1-(4-氟苯基)-1-(3-甲胺-[3-d2]-丙基)-1,3-二氢-异苯并呋喃-5-氰化物(11)是通过多步合成法从西酞普兰(4)合成的,并用作合成[11C]-13的前体。与报道的气相合成[11C]碘甲烷类似,本研究报告了[11C]重氘碘甲烷的首次气相合成。研究了与合成化合物相关的1H/2H动力学同位素效应,在体外大鼠研究中比较了示踪剂[11C]-4、[11C]-12和[11C]-13在小脑等感兴趣脑区的比率。数据表明,在注射三种示踪剂后,任何被调查脑区的结合没有显著差异。版权所有 © 2004 John Wiley & Sons, Ltd.