In:
Journal of Labelled Compounds and Radiopharmaceuticals, Wiley, Vol. 53, No. 3 ( 2010-03), p. 113-119
Abstract:
As model reactions for the introduction of 18 F into protected aromatic amino acids, the replacement of NO 2 , Cl, Br and F by [ 18 F]fluoride in 2‐isophthalaldehyde and 2‐terephthalaldehyde derivatives which model 18 F‐DOPA and 18 F‐tyrosine was investigated by comparing labelling yields and reaction rates with those of corresponding mono‐aldehyde compounds. All isophthalaldehydes showed maximum radiochemical yields (79 to 86%) at 140°C and in comparison with the corresponding mono‐aldehydes the reaction proceeded faster. At lower temperature the reaction already resulted in high yields, e.g. 2‐nitroisophthalaldehyde was labelled with a yield of 78% at 25°C after 7 min, whereas 2‐nitrobenzaldehyde only reached a yield of 1.7% under the same reaction conditions. The 18 F/NO 2 exchange in nitroterephthalaldehydes proceeded more slowly and with lower radiochemical yields when compared with corresponding isophthalaldehydes and monoaldehydes. The decarbonylation of 18 F‐labelled aromatic dialdehydic compounds with 4 eq. of Wilkinson's catalyst at 150°C in benzonitrile resulted in high yields, e.g. 2‐[ 18 F]fluoro‐5‐methoxyisophthalaldehyde and 4‐[ 18 F]fluoro‐2‐methoxy‐5‐methylisophthalaldehyde were decarbonylated efficiently with yields of 67±3% and 72±2%, respectively. Copyright © 2010 John Wiley & Sons, Ltd.
Type of Medium:
Online Resource
ISSN:
0362-4803
,
1099-1344
Language:
English
Publisher:
Wiley
Publication Date:
2010
detail.hit.zdb_id:
1491841-9
SSG:
15,3
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