Chaly T, Diksic M
J Nucl Med. 1986 Dec;27(12):1896-901.
Regioselective fluorination of a completely protected phosgene derivative of 3,4-dihydroxy-phenyl-L-alanine (5-(benzyl-3',4'-carbonate)-oxazolidine-2,5-dione) with gaseous 18F-labeled acetylhypofluorite and [18F]F2 in acetonitrile is described. Fluorination with [18F]acetylhypofluorite yields 6-[18F]fluoro-L-dopa with 95% radiochemical purity; fluorination of the same substrate with [18F]F2 yields a mixture of all three structural isomers in a ratio of 70:16:14 for 6-, 5-, and 2-fluoro compounds. Radiochemical yield, relative to [18F] acetylhypofluorite, measured at the end of the synthesis, is (21 +/- 4)% (N = 8). The synthesis requires approximately 40 min (50 min if HPLC was done) and yields the final radiopharmaceutical in a two-step procedure. The specific activity of the final product was approximately 763 mCi/mmol at the end of a 40-min synthesis when 30-min irradiation was used.
描述了在乙腈中用气态(^{18}F)标记的乙酰次氟酸酯和([^{18}F]F_2)对完全保护的3,4 - 二羟基 - 苯基 - L - 丙氨酸（5 -（苄基 - 3',4'-碳酸酯） - 恶唑烷 - 2,5 - 二酮）的光气衍生物进行区域选择性氟化。用([^{18}F])乙酰次氟酸酯氟化得到放射化学纯度为95%的6 - ([^{18}F])氟 - L - 多巴；用([^{18}F]F_2)对相同底物进行氟化得到所有三种结构异构体的混合物，6 - 、5 - 和2 - 氟化合物的比例为70:16:14。相对于([^{18}F])乙酰次氟酸酯，在合成结束时测得的放射化学产率为(21 ± 4)%（(N = 8)）。该合成需要约40分钟（如果进行高效液相色谱则为50分钟），并通过两步法得到最终放射性药物。当使用30分钟辐照时，在40分钟合成结束时，最终产物的比活度约为763 mCi/mmol。
