Preparation of fluorine-18-labelled fluoromisonidazole using two different synthesis methods
作者:Eeva-Liisa Kämäräinen、Teija Kyllönen、Outi Nihtilä、Heikki Björk、Olof Solin
DOI:10.1002/jlcr.795
日期:2004.1
18F-labelled fluoromisonidazole [1H-1-(3-[18F]fluoro-2-hydroxypropyl)-2-nitroimida-zole; ([18F]FMISO)] is used as an in vivo marker of hypoxic cells in tumours and ischaemic areas of the heart and the brain. The compound plays an important role in evaluating the oxygenation status in tumours during radiotherapy. In this paper, we report experiments carried out in our laboratory in synthesizing [18F]FMISO using two different methods. The first method (I) for the [18F]FMISO synthesis was the fluorination of (2R)-(−)-glycidyl tosylate to [18F]epifluorohydrin. The subsequent nucleophilic ring opening, achieved with 2-nitroimidazole, leads to labelled FMISO. The second method (II) was the fluorination of the protected precursor 1-(2′-nitro-1′-imidazolyl)-2-O-tetrahydropyranyl-3-O-toluenesulphonyl-propanediol, followed by a rapid removal of the protecting group. With the first method, the radiochemical yield was about 10% at the end of the synthesis (EOS), and the radiochemical purity was over 99%. The radiochemical yield in the second method was 21% (EOS) on an average, and the radiochemical purity was over 97%. When an automated commercial synthesis module was used with method II, slightly better and more reproducible yields were achieved. The improvement in the synthesis yield with the automated apparatus will be valuable when working with high activities, and therefore it is under further development. Copyright © 2003 John Wiley & Sons, Ltd.
18F 标记的氟咪唑[1H-1-(3-[18F]氟-2-羟基丙基)-2-硝基咪唑;([18F]FMISO)]被用作肿瘤以及心脏和大脑缺血区域缺氧细胞的体内标记物。该化合物在放疗期间评估肿瘤氧合状态方面发挥着重要作用。本文报告了我们实验室使用两种不同方法合成 [18F]FMISO 的实验。合成[18F]FMISO的第一种方法(I)是将(2R)-(-)-缩水甘油对甲苯磺酸盐氟化为[18F]环氟醇。随后用 2-硝基咪唑进行亲核开环,得到标记的 FMISO。第二种方法(II)是将受保护的前体 1-(2′-硝基-1′-咪唑基)-2-O-四氢吡喃基-3-O-甲苯磺酰基丙二醇氟化,然后迅速去除保护基。采用第一种方法,合成结束时的放射化学收率(EOS)约为 10%,放射化学纯度超过 99%。第二种方法的放射化学收率平均为 21%(EOS),放射化学纯度超过 97%。在第二种方法中使用自动商业合成模块时,产量略高,且可重复性更好。使用自动化设备提高合成产量对高活性工作很有价值,因此正在进一步开发中。Copyright © 2003 John Wiley & Sons, Ltd. All Rights Reserved.