Synthesis of diethyl [carbonyl-C-11]malonate from [C-11]carbon monoxide by rhodium-promoted carbonylation and its application as a reaction intermediate
2006 (English)In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 49, no 9, 801-809 p.Article in journal (Refereed) Published
Rhodium-mediated carbonylation reaction was applied to synthesize diethyl [carbonyl-C-11]malonate using [C-11]carbon monoxide at low concentration. The synthesis was performed starting with ethyl diazoacetate, ethanol and the rhodium complex being made in situ by chloro(1,5-cyclooctadiene)rhodium(l) dimer ([Rh(cod)Cl](2)) and 1,2-bis(diphenylphosphino)ethane (dppe), and the reaction is assumed to proceed via a ketene intermediate. The isolated radiochemical yield was 20% (75% analytical radiochemical yield) and the trapping efficiency of [C-11]carbon monoxide in the order of 85%. The specific radioactivity of this compound was measured at 127 GBq/mu mol (7.28 nmol total mass) after 8 mu Ah bombardment and 35 min synthesis. The corresponding C-13-labelled compound was synthesized using (C-13)carbon monoxide to confirm the position of the carbonyl-labelled atom by C-13-NMR. Diethyl [carbonyl-C-11]malonate was further used in subsequent alkylation step using ethyl iodide and tetrabutylammonium fluoride to obtain diethyl diethyl [carbonyl-C-11]malonate in 50% analytical radiochemical yield.
Place, publisher, year, edition, pages
2006. Vol. 49, no 9, 801-809 p.
diethyl [carbonyl-C-11]malonate, [C-11]carbon monoxide, rhodium-mediated carbonylation reaction, ketene
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-94173DOI: 10.1002/jlcr.1098ISI: 000240473200005OAI: oai:DiVA.org:uu-94173DiVA: diva2:167933