Electrochemical radiofluorination. 3. Direct labeling of phenylalanine derivatives with [18F]fluoride after anodic oxidation
作者:Gabriele J. Kienzle、Gerald Reischl、H.-J�rgen Machulla
DOI:10.1002/jlcr.918
日期:2005.3.30
As an example of applying the electrochemical method in radiofluorination a new procedure was developed for preparing [18F]fluorophenylalanine by direct use of [18F]fluoride. Several protecting groups for amino and carboxylic function of phenylalanine were investigated. Best results were obtained for N-trifluoroacetylphenylalanine methyl ester (1) (10.5±2.5%) with a relative isomeric distribution of
作为在放射性氟化中应用电化学方法的一个例子,开发了一种通过直接使用 [18F] 氟化物制备 [18F] 氟苯丙氨酸的新程序。研究了苯丙氨酸的氨基和羧基功能的几个保护基团。N-三氟乙酰苯丙氨酸甲酯 (1) (10.5±2.5%) 获得了最佳结果,其相对异构体分布为 50.5±1.5% 的邻位异构体、11.5±1.5% 的间位异构体和 38.8±2.1% 的对位异构体。优化的反应条件是使用 Et3N·3HF 作为支持电解质,温度在 0 到 –10°C 之间。通过工作电位 (1.5–2.0 V) 和氯化物浓度(作为支持电解质添加,0.0–0. 36 M) 证明间接电解作为反应机制或卤素交换 (halex) 反应,主要形成氯化产物,然后进行卤素交换是极不可能的。版权所有 © 2005 John Wiley & Sons, Ltd.