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The development of an efficient, rapid method for [^<18>F] fluorobenzyl iodide as a versatile labeling precursor.

开发了一种有效、快速的方法，用于将[^ 18 F]氟苄基碘作为多功能标记前体。

基本信息

批准号：
11670861
负责人：
IWATA Ren
金额：
$ 2.11万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

[^<18>F] Fluorobenzyl iodide and bromide ([^<18>F] fluorobenzyl halide) have been expected to be as versatile a precursor for ^<18>F-fluorobenzylation as ^<11>C-labled methyl iodide for ^<11>C-methylation. In the present study, we have aimed at developing a convenient, rapid method for automated preparation of the target compound from [^<18>F] fluoride. Attempts have been made to adapt the following three steps, constituting the synthesis procedure, to on-column processing.1) Synthesis of [^<18>F] fluorobenzaldehyde from [^<18>F] fluoride : Starting substrates were immobilized on solid-phase-supports and examined for aromatic nucleophilic substitution by [^<18>F] fluoride. However, radiochemical yields of [^<18>F] fluorobenzaldehyde obtained by this method were not high enough for successive reactions. Consequently the on-column method was abandoned.2) Reduction of [^<18>F] fluorobenzaldehyde into [^<18>F] fluorobenzyl alcohol : Sodium borohydride was chosen among many reductive reagents as it was used in aqueous solutions. While NaBH_4 on alumina gave rather lower yields, a simple on-column method of just flowing a NaBH_4 solution through a C18 cartridge retaining [^<18>F] fluorobenzaldehyde yielded [^<18>F] fluorobenzyl alcohol almost quantitatively. Thus after the reduction [^<18>F] fluorobenzyl alcohol was eluted with CH_2Cl_2.3) Synthesis of [^<18>F] fluorobenzyl halide from [^<18>F] fluorobenzyl alcohol : Halogenation reagents immobilized to a resin or adsorbed on silica gel were investigated for the reaction. It was observed that radiochemical yields of [^<18>F] fluorobenzyl halide were very dependent on the dryness of the solvent eluting from the C18 cartridge. A semi-automated system was constructed on the basis of the above results and evaluated by preparing new ^<18>F-labeled radioligands from [^<18>F] fluorobenzyl halide.

[^&lt；18&gt；F]氟苄基碘和溴([^&lt；18&gt；F]氟苄基卤化物)被认为是用于^&lt；18&gt；F-甲基化的多功能性前体，就像用于^&lt；11&gt；C-甲基化的C-标记的甲基碘一样。在本研究中，我们的目标是开发一种方便、快速的方法，用于从氟化物中自动制备目标化合物。已经尝试使以下三个步骤适合于柱上处理：1)从氟化物合成[18F]氟苯甲醛：将起始底物固定在固相载体上，并检测[18F]氟化物的芳香族亲核取代反应。然而，用这种方法得到的[^&lt；18&gt；F]氟苯甲醛的放化产率不足以进行后续反应。2)将[^&lt；18&gt；F]氟苯甲醛还原为[^&lt；18&gt；F]氟苯甲醇：由于在水溶液中使用，因此在许多还原试剂中选择了硼氢化钠。而NaBH_4在氧化铝上的产率较低，一种简单的柱上方法，只需将NaBH_4溶液流过C18色谱柱，保留[18F]氟苯甲醛，就几乎定量地生成了[18F]氟苯甲醇。因此，在还原后，用CH_2Cl2.3)洗脱[^&lt；18&gt；F]氟苯甲醇。从[^&lt；18&gt；F]氟苄醇合成[^&lt；18&gt；F]氟苄基卤化物：考察了固定在树脂上或吸附在硅胶上的卤代试剂的反应。观察到[^&lt；18&gt；F]氟苯卤化物的放化产率很大程度上取决于从C18色谱柱洗脱的溶剂的干燥程度。在上述结果的基础上，构建了一个半自动体系，并通过从氟苯卤化物制备新的放射性配体进行了评价。