No-carrier-added regioselective preparation of 6-[18F]fluoro-L-dopa.
This paper describes the preparation of 6-[18F]fluoro-L-dopa by a no-carrier-added method based on the nucleophilic displacement of nitro groups of two commercially available substrates, 3,4-dimethoxy-2-nitrobenzaldehyde (nitroveratraldehyde) and 6-nitropiperonal. Fluorination was conducted in DMSO with fluorine-18 (18F) in the presence of the aminopolyether Kryptofix 222 and potassium carbonate. The condensation of the fluorinated aldehydes with phenyloxazolone and the subsequent hydrolysis with HI/P yield, after purification by HPLC, only the 6-(D, L) isomers. The racemic mixture (50/50) was resolved on an analytical scale chiral column. The method, which requires 100 min (EOB) to complete, produces 6-[18F]fluoro-L-dopa with a decay-corrected radiochemical yield of 10%, an enantiomeric purity greater than 99%, and a specific activity of 1.2 Ci/mumole.
Lemaire
C
C
Cyclotron Research Center, Liege University, Belgium.
Guillaume
M
M
Cantineau
R
R
Christiaens
L
L
D001547:Benzaldehydes; D002851:Chromatography, High Pressure Liquid; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D004121:Dimethyl Sulfoxide; D005462:Fluorine Radioisotopes; D006868:Hydrolysis
D001547:Benzaldehydes; D005462:Fluorine Radioisotopes; C064768:nitroveratraldehyde; C043437:fluorodopa F 18; D004295:Dihydroxyphenylalanine; C064767:6-nitropiperonal; D004121:Dimethyl Sulfoxide