Efficient regioselective labelling of the CFC alternative 1,1,1,2-tetrafluoroethane (HFC-134a) with fluorine-18
作者:Franklin I. Aigbirhio、Victor W. Pike、Stephen L. Waters、Richard J.N. Tanner
DOI:10.1016/0022-1139(94)03138-p
日期:1995.2
the 1-position by nucleophilic addition and 91.2±1.2% for labelling in the 2-position by nucleophilic substitution. GC separation afforded each labelled tetrafluoroethane in high radiochemical purity (>99.995%) and high chemical purity (>99.6%). Specific radioactivities of about 37 MBq (1 mCi) per μmol were obtained. Each synthesis was fully automated to cope safely with the high initial radioactivity
描述了一种有效的化学方法,用于用回旋加速器产生的发射正电子的氟18(最小)对CFC替代品1,1,1,2-四氟乙烷进行区域选择性标记。[1- 18 F] 1,1,1,2-四氟乙烷是通过向三氟乙烯和[2- 18 F] 1,1,1,2-四氟乙烷亲核加成无载体的[ 18 F]氟化物而制备的。用[ 18 F]氟化物在对甲苯磺酸2,2,2-三氟乙基酯中对甲苯磺酸酯进行亲核取代。各反应通过一个钾阳离子的Kryptofix介导®2.2.2在密封的玻璃碳容器中,有或无乙腈为溶剂的络合物。通过亲核加成标记在1-位的选择性为97.2±0.4%,通过亲核取代标记在2-位标记的选择性为91.2±1.2%。气相色谱分离得到高放射性化学纯度(> 99.995%)和高化学纯度(> 99.6%)的每种标记的四氟乙烷。获得约37 MBq(1 mCi)/μmol的比放射性。每种合成都是全自动的,可以安全地应对较高的初始放射性,