Synthesis ofN-(2,5-dimethoxybenzyl)-N-(5-fluoro-2-phenoxyphenyl)[carbonyl-11C]acetamide ([carbonyl-11C]DAA1106) and analogues using [11C]carbon monoxide and palladium(0) complex
作者:Obaidur Rahman、Bengt Långström
DOI:10.1002/jlcr.1437
日期:2007.11
N-(2,5-Dimethoxybenzyl)-N-(5-fluoro-2-phenoxyphenyl)acetamide (DAA1106), a potent and selective ligand for peripheral benzodiazepine receptor, and eight structurally related analogues were labelled with 11C at the carbonyl position using a low concentration of [11C]carbon monoxide and the micro-autoclave technique. A combinatorial approach was applied to synthesize the analogues using similar reaction conditions. Palladium-mediated carbonylation using tetrakis(triphenylphosphine)palladium, various amines and methyl iodide or iodobenzene was employed in the synthesis. The 11C-labelled products were obtained with 10–55% decay-corrected radiochemical yields and the final product was more than 97% pure in all cases. Specific radioactivity was determined for the compound [carbonyl-11C]DAA1106 using a single experiment and a 10-µA h bombardment. The specific radioactivity, measured 36 min after end of bombardment, was 455 GBq/µmol. Synthetic routes to the precursors and reference compounds were also developed. The presented approach is a novel method for the synthesis of [carbonyl-11C]DAA1106 and its analogues, and allows the formation of a library of 11C-labelled DAA1106 analogues which can be used to optimize the performance as a potential positron emission tomography tracer. Copyright © 2007 John Wiley & Sons, Ltd.
N-(2,5-二甲氧基苄基)-N-(5-氟-2-苯氧苯基)乙酰胺(DAA1106),一种强效且选择性的外周苯二氮卓受体配体,及其八个结构相关的类似物,使用低浓度的[11C]一氧化碳和微型高压釜技术在羰基位置进行了11C标记。采用组合方法,利用相似的反应条件合成了这些类似物。合成中使用了四(三苯膦)钯介导的羰基化反应,并结合了各种胺和甲基碘或碘苯。所得的11C标记产物具有10-55%的衰变校正放射化学产率,所有情况下最终产物纯度均超过97%。通过单次实验和10µA h轰击,测定了化合物[羰基-11C]DAA1106的比活度。轰击结束后36分钟测得的比活度为455 GBq/µmol。还开发了合成前体和参考化合物的路线。所提出的方法是一种新颖的[羰基-11C]DAA1106及其类似物的合成方法,并能够形成一系列11C标记的DAA1106类似物库,这些类似物可用于优化其作为潜在正电子发射断层扫描示踪剂的性能。版权所有 © 2007 John Wiley & Sons, Ltd.