F. Karimi, B. Långström
Mar 11, 2002
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0
Influential Citations
23
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Journal
Journal of Labelled Compounds and Radiopharmaceuticals
Abstract
3-[(2S)-azetidin-2-ylmethoxy]-5-[11C]-methylpyridine (5d), which might be a novel ligand for nicotinic receptors, was synthesized via coupling [11C]iodomethane with tert-butyl (2S)-2-({[5-(trimethylstannyl)pyridin-3-yl]oxy}methyl) azetidine-1-carboxylate (4) at 80°C for 5 min with tri-o-tolylphosphine-bound, unsaturated palladium(0), followed by deprotection using trifluoroacetic acid (TFA). The previous problem (solid-phase extraction before injection on semi-preparative LC) with automation of Stille coupling reactions has been overcome. In a typical experiment, 0.46 GBq of 5d was obtained from 5.2 GBq of [11C]iodomethane. The decay-corrected radiochemical yield was 39% (based on the quantity [11C]iodomethane trapped). The synthesis time was 43 min from end of radionuclide production. During a production condition using 36 μAh of proton beam irradiation, a specific radioactivity of 50 GBq/μmol of the final product was obtained in biological buffer. Copyright © 2002 John Wiley & Sons, Ltd.