Ermert, J. (Corresponding author)FZJ*

1998
Forschungszentrum, Zentralbibliothek Jülich

Report No.: Juel-3499

Abstract: A new pathway for the no carrier added (n.c.a.) l'F-labelling of biogenic arylalkylamines such as C"Flfluoronorephedrine and [l'F]fluorometaraminol (FMR) via nucleophilic aromatic substitution was developed. To overcome the problem of low specific activity, not to avoid with previous electrophilic fluorination, l'F-labelled arylalkylamines were synthesized by direct nucleophilic exchange with n.c.a. C8F]fluoride starting with a keto-activated aromatic system and consecutive chiral reduction of the ketofunction. With regard to a stereosclective reduction of the carbonyl group, several N-protected cc-aminopropiophenones were prepared as model compounds in order to examine the influence of the protecting group on the radiochemical yield of a l'F-for-X substitution (X= F, Cl, NO" "N(CH3),) . Good radiochemical yields could be achieved using the N-dibenzyl- or acetyl-protected compounds. The para-position of the leaving group provided higher radiochemical yields than the ortho-position in the case of the l'F-forY'F substitution. It has been shown that the less basic oxalate/cryptate system does not increase the radiochemical yields.

Keyword(s): labeled compound ; fluorination

1. Nuklearchemie (INB-4)