Synthesis of [11C](−)-α,α-dideutero-phenylephrine for in vivo kinetic isotope studies
作者:R. B. Del Rosario、D. M. Wieland
DOI:10.1002/jlcr.2580360703
日期:1995.7
(−)-[11C]Phenylephrine and positron emission tomography could potentially be used to assess neuronal monoamine oxidase activity in the heart. Previous data for (−)-(11C]phenylephrine indicate that, although its retention and neuronal selectivity parallel that of the neuronal mapping agent (−)-[11C]hydroxyephedrine, its neuronal storage and clearance properties are quite different. In order to study the in vivo kinetics of (−)-[11C]phenylephrine in greater detail, the dideutero analog [11C]-(−)-α,α-dideutero-phenylephrine, 1, was synthesized by [11C]methylation of the precursor (−)-α,α-dideutero-m-octopamine. The key step in the procedure was BD3 reduction of the cyanohydrin derived from 3-hydroxybenzaldehyde. Deuterium incorporation at the alpha positions of m-octopamine was confirmed by NMR and mass spectroscopy of the deuterated product and by comparison of spectral data with undeuterated m-octopamine. (−)-α,α-Dideutero-m-octopamine was methylated with CF3SO311CH3 to give 1 suitable for animal and clinical studies.
(−)-[11C]苯肾上腺素和正电子发射断层扫描可能被用于评估心脏中的神经单胺氧化酶活性。以前的数据显示,(−)-[11C]苯肾上腺素的保留和神经选择性与神经成像剂(−)-[11C]羟基麻黄碱的表现相似,但其神经储存和清除特性则截然不同。为了更详细地研究(−)-[11C]苯肾上腺素在体内的动力学,合成了二重氘类药物[11C]-(−)-α,α-二氘-苯肾上腺素1,方法是通过[11C]甲基化前体(−)-α,α-二氘-邻苯二胺。该过程的关键步骤是用BD3还原从3-羟基苯甲醛衍生的氰醇。通过对氘化产物进行NMR和质谱分析,以及与未氘化的邻苯二胺的光谱数据比较,确认了在邻苯二胺的α位点的氘掺入。将(−)-α,α-二氘-邻苯二胺与CF3SO311CH3甲基化,以获得适合动物和临床研究的1。