Division of Nuclear Medicine and Molecular Imaging, Boston Children's Hospital, Boston, MA, 02115, USA.
Harvard Medical School, Boston, MA, 02115, USA.
Sci Rep. 2020 Apr 22;10(1):6818. doi: 10.1038/s41598-020-61845-y.
Fluorine-18 radiolabeling typically includes several conserved steps including elution of the [F]fluoride from an anion exchange cartridge with a basic solution of KCO or KHCO and Kryptofix 2.2.2. in mixture of acetonitrile and water followed by rigorous azeotropic drying to remove the water. In this work we describe an alternative "non-anhydrous, minimally basic" ("NAMB") technique that simplifies the process and avoids the basic conditions that can sometimes limit the scope and efficiency of [F]fluoride incorporation chemistry. In this approach, [F]F is eluted from small (10-12 mg) anion-exchange cartridges with solutions of tetraethylammonium bicarbonate, perchlorate or tosylate in polar aprotic solvents containing 10-50% water. After dilution with additional aprotic solvent, these solutions are used directly in nucleophilic aromatic and aliphatic F-fluorination reactions, obviating the need for azeotropic drying. Perchlorate and tosylate are minimally basic anions that are nevertheless suitable for removal of [F]F from the anion-exchange cartridge. As proof-of-principle, "NAMB" chemistry was utilized for the synthesis of the dopamine D/D antagonist [F]fallypride.
氟-18 放射性标记通常包括几个保守步骤,包括用碳酸钾或碳酸氢钾和 Kryptofix 2.2.2 的碱性溶液从阴离子交换柱中洗脱[F]氟化物,并在乙腈和水的混合物中进行严格的共沸干燥以除去水。在这项工作中,我们描述了一种替代的“非无水、最小碱性”(“NAMB”)技术,该技术简化了该过程,并避免了有时会限制[F]氟化物结合化学的范围和效率的碱性条件。在这种方法中,[F]F 从小(10-12mg)阴离子交换柱中用四乙铵碳酸氢盐、高氯酸盐或对甲苯磺酸盐在含有 10-50%水的非质子性亲脂性溶剂中洗脱。用额外的非质子性溶剂稀释后,这些溶液可直接用于亲核芳香族和脂肪族 F-氟化反应,无需进行共沸干燥。高氯酸盐和对甲苯磺酸盐是最小碱性的阴离子,但仍适合从阴离子交换柱中去除[F]F。作为原理验证,“NAMB”化学被用于多巴胺 D/D 拮抗剂[F]氟苯丙胺的合成。