A process is provided for producing a labeled precursor which is useful for production of a radioactive fluorine-labeled amino acid compound. In the reaction step for introducing a leaving group to a mixture of syn-form and anti-form of FACBC, a base is allowed to present in the reaction system to produce a syn-leaving group adduct, which is unreactive with the base and is highly stable, and an anti-leaving group adduct which can react with the base to form a water-soluble compound. By employing a purification method utilizing such a difference in solubility, the syn-leaving group adduct can be separated selectively. The base may be a linear- or branched-chain primary to tertiary alkylamine having 1 to 10 carbon atoms, a nitrogen-containing heterocyclic compound with 2 to 20 carbon atoms, and a nitrogen-containing hetero aromatic compound with 2 to 20 carbon atoms.
提供了一种生产标记前体的方法,该前体可用于制备放射性
氟标记的
氨基酸化合物。在引入离去基到FACBC的同构体和反构体的混合物的反应步骤中,允许碱存在于反应系统中,以产生一个与碱不反应且高度稳定的同构体离去基加合物和一个可与碱反应形成
水溶性化合物的反构体离去基加合物。通过利用这种溶解度差异的纯化方法,可以选择性地分离同构体离去基加合物。碱可以是具有1到10个碳原子的线性或支链初级到三级烷基胺,具有2到20个碳原子的含氮
杂环化合物和具有2到20个碳原子的含氮杂芳香化合物。