Selectivity of elemental fluorine towards l-tyrosine and l-α-methyltyrosine in acidic media and the syntheses of their []3-fluoro and []3,5-difluoro derivatives
作者:Neil Vasdev、Raman Chirakal、Gary J. Schrobilgen、Claude Nahmias
DOI:10.1016/s0022-1139(01)00406-7
日期:2001.9
tyrosine derivatives resulted when solvent mixtures containing BF3 added to anhydrous HF (aHF) were used. Lower yields in BF3/aHF have been studied by use of low-temperature (−70°C) and NMR spectroscopy of l-α-MT, which showed deactivation of the aromatic ring in BF3/aHF. Improved isocratic preparative and analytical HPLC methods for the separation of the fluorinated tyrosine derivatives were also
已知1-酪氨酸和1-α-甲基酪氨酸(1-α-MT)的氟化衍生物对于利用正电子发射断层摄影术的医学成像是有用的示踪剂。在不同的酸性介质中,用[ ] F 2对1-酪氨酸和1-α-MT进行直接氟化反应表明,随着反应介质酸度的增加,3-氟异构体的放射化学收率增加。当使用添加到无水HF(aHF)中的含BF 3的溶剂混合物时,酪氨酸衍生物的3,5-二氟异构体的3,5-二氟异构体的放射化学产率降低,产量增加。通过使用低温(-70°C)和l-α-MT的NMR光谱研究了BF 3 / aHF的较低收率,这表明BF 3中的芳环失活了/ aHF。还开发了用于分离氟化酪氨酸衍生物的改进的等度制备和分析HPLC方法。本研究中合成的所有化合物均通过NMR光谱和质谱进行表征。