<i>N</i>,<i>N</i>,<i>N</i>-Trimethyl-5-[(2,3,5,6-tetrafluorophenoxy)carbonyl]pyridin-2-aminium trifluoromethanesulfonate a precursor for the synthesis of 2,3,5,6-tetrafluorophenyl 6-[<sup>18</sup>F]-fluoronicotinate
作者:Ryan A. Davis、James C. Fettinger
DOI:10.1107/s2053229618005430
日期:2018.5.1
PyTFP‐precursor, displacement of a Cl atom with trimethylamine gas and anion replacement with a triflate counter‐ion is critical, as incomplete replacement would hinder radioisotopic incorporation of nucleophilic fluorine‐18 and result in diminished radiochemical yields. The structural determination of the PyTFP‐precursor by X‐ray crystallography helped confirm the anion exchange of chloride with triflate.
的合成,重结晶,和透视deterimination Ñ,Ñ,Ñ [(2,3,5,6- tetrafluorophenoxy)羰基]吡啶-2-铵三氟甲磺酸酯(PyTFP前体),C - -三甲基- 5 15 ħ 13 ˚F 4 ñ 2 ö 2 + ·CF 3 SO 3 - ,进行说明。该三氟甲磺酸盐前体是合成2,3,5,6-四氟苯基6- [ 18 F] -氟代烟酸酯([ 18F] FPyTFP),一个用于对正电子发射断层扫描(PET)进行放射性标记肽的修复基团,因为该肽正越来越多地在核医学中用作PET成像探针。肽的放射性标记通常使用“辅基”完成,第一步是放射性同位素附着在其上的小合成子,然后在第二步中附着到肽上。在PyTFP前体的合成过程中,用三甲胺气体置换Cl原子并用三氟甲磺酸酯抗衡离子置换阴离子非常关键,因为置换不完全会阻碍放射性同位素掺入亲核氟18并导致放射化学收率降低。通过X射线晶体学