2-(4-Methoxyphenyl)-N-(4-methylbenzyl)-N-(1-methylpiperidin-4-yl)acetamide (AC90179, 4), a highly potent and selective competitive 5-HT2A antagonist, was labeled by [11C]-methylation of the corresponding desmethyl analogue 5 with [11C]methyl triflate. The precursor molecule 5 for radiolabeling was synthesized from p-tolylmethylamine in three steps with 46% overall yield. [11C]AC90179 was synthesized in 30 min (30 ± 5% yield, EOS) with a specific activity of 4500 ± 500 Ci/mmol and >99% chemical and radiochemical purities. Positron emission tomography studies in anesthetized baboon revealed that [11C]4 Penetrates the blood–brain barrier (BBB) with a rapid influx and efflux of the tracer in all brain regions. Due to lack of tracer retention or specific binding, [11C]4 cannot be used as PET ligand for imaging 5-HT2A receptors. Copyright © 2006 John Wiley & Sons, Ltd.
                                    2-(4-
甲氧基苯基)-N-(4-甲基苄基)-N-(
1-甲基哌啶-4-基)乙酰胺(AC90179,4)是一种高效力和高选择性的竞争性 5-HT2A 拮抗剂,用 [11C]methyl triflate 对相应的去甲基类似物 5 进行[11C]甲基化标记。用于放射性标记的前体分子 5 是由对
甲苯甲胺分三步合成的,总收率为 46%。[11C]AC90179在30分钟内合成完成(收率为30±5%,EOS),比活度为4500±500 Ci/mmol,
化学纯度和放射
化学纯度均大于99%。在麻醉狒狒体内进行的正电子发射断层扫描研究显示,[11C]4 能穿透血脑屏障(BBB),并在所有脑区快速流入和流出示踪剂。由于缺乏示踪剂保留或特异性结合,[11C]4 不能用作 5-HT2A 受体成像的 PET 
配体。Copyright © 2006 John Wiley & Sons, Ltd. All Rights Reserved.