title: Radiosynthesis of NCA [carbonyl-11C]6-fluoromelatonin.
abstract: A method is described for the preparation of [carbonyl-11C]6-fluoromelatonin for intravenous injection and potential study of the melatonin system in vivo by positron emission tomography. The preparation is based on the acetylation of 6-fluoro-5-methoxytryptamine with NCA [1-11C]acetyl chloride (itself prepared from cyclotron-produced [11C]carbon dioxide) and purification by HPLC. It gives chemically and radiochemically pure [carbonyl-11C]6-fluoromelatonin in 35% radiochemical yield (from [11C]CO2, decay-corrected) within 35 min from the end of radionuclide production and with high specific activity e.g. 1.6 GBq/mumol (43 mCi/mumol) at the end of synthesis from 1.1 GBq (30 mCi) of [11C]carbon dioxide.
authors.affiliation: MRC Cyclotron Unit, Hammersmith Hospital, London, U.K.
authors.forename: D
authors.initials: D
authors.lastname: Le Bars
authors.forename: S K
authors.initials: SK
authors.lastname: Luthra
authors.forename: V W
authors.initials: VW
authors.lastname: Pike
authors.forename: K L
authors.initials: KL
authors.lastname: Kirk
mesh_terms: D002250:Carbon Radioisotopes; D007553:Isotope Labeling / Q000379:methods; D008550:Melatonin / Q000031:analogs & derivatives* / Q000138:chemical synthesis
chemical_list: D002250:Carbon Radioisotopes; C022598:6-fluoromelatonin; D008550:Melatonin