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@INPROCEEDINGS{Craig:865321,
author = {Craig, A. and Kolks, N. and Urusova, E. and Zlatopolskiy,
Boris and Neumaier, B.},
title = {{T}he {E}fficient {P}reparation of {R}adiolabeled
{A}romatic {A}mino {A}cids via {C}u-{M}ediated
{R}adiofluorination using {N}i-complexes},
reportid = {FZJ-2019-04823},
year = {2019},
abstract = {Ziel/Aim:The aim of this work was to develop a procedure
for the preparation of F-18-labeled aromatic amino acids
(AAA) via alcohol-enhanced Cu-mediated radiofluorination
using Ni-BPX auxiliaries as easily-removable dual-protecting
groups.Methodik/Methods:The Bpin-substituted precursors of
radiofluorinated AAA and α-Me-AAA were prepared by
alkylation of (S)-Ni-BPB-Gly and (S)-Ni-BPA-(RS)-Ala with
the corresponding Bpin-substituted benzyl bromides.
Radiolabeling was carried out according to the protocol for
alcohol-enhanced1 Cu-mediated radiofluorination as follows:
F-18-F- was loaded onto a QMA-cartridge which was
subsequently washed with MeOH; F-18-F- was eluted with
Et4NHCO3 to a solution of Cu(py)4(OTf)2 and precursor in
DMF/nBuOH (2:1), and the reaction mixture was stirred under
air at 110 °C for 10 min. Evaporation of the DMA/nBuOH was
followed by deprotection using 12 M HCl at 110 °C for 15
min. The acidic solution was evaporated and the tracer was
isolated by HPLC.Ergebnisse/Results:Ni complexes containing
2 – 4-F-18-FPhe, 2 – 4-aMe-F-18-FPhe, 6-F-18-FMT,
aMe-6-F-18-FMT, 4-F-18-FTrp and 2-Me-F-18-FTyr residues were
obtained in RCCs of 50 – $95\%.$ The purified tracers were
isolated in n.d.c 15 – $25\%$ RCYs in excellent
radiochemical and enantiomeric purity. Radiosyntheses of
4-F-18-FPhe and 4-F-18-FTrp were implemented to an automated
module furnishing tracers in n.d.c RCYs of $25\%$ and
$17\%,$ respectively, within 75 – 80
min.Schlussfolgerungen/Conclusions:Alcohol-enhanced
Cu-mediated radiofluorination of BPin substituted Ni-BPX-AAA
complexes is a simple, yet powerful method for the fast
production of structurally diverse radiolabeled AAAs and
alpha-methyl substituted AAAs. The attractiveness of the
procedure is highlighted by the accessibility of
radiolabeling precursors, high RCYs and easy implementation
to an automated module.Literatur/References:[1] Zichler, J.,
Niklas, K., Modemann, D., Neumaier, B., Zlatopolskiy, B.;
Chemistry – A European Journal, 2017, 23, 3251 – 3256},
month = {Apr},
date = {2019-04-03},
organization = {57. Jahrestagung der Deutschen
Gesellschaft für Nuklearmedizin,
Bremen (Germany), 3 Apr 2019 - 6 Apr
2019},
subtyp = {After Call},
cin = {INM-5},
cid = {I:(DE-Juel1)INM-5-20090406},
pnm = {573 - Neuroimaging (POF3-573)},
pid = {G:(DE-HGF)POF3-573},
typ = {PUB:(DE-HGF)6},
doi = {10.1055/s-0039-1683568},
url = {https://juser.fz-juelich.de/record/865321},
}