<p>Compounds labelled with <sup>11</sup>C (<i>β</i><sup>+</sup>, t<sub>1/2</sub> = 20.4 min) are used in positron emission tomography (PET), which is a quantitative non-invasive molecular imaging technique. It utilizes computerized reconstruction methods to produce time-resolved images of the radioactivity distribution in living subjects. </p><p>The feasibility of preparing [<sup>11</sup>C]methyl iodide from [<sup>11</sup>C]methane and iodine via a single pass through a non-thermal plasma reactor was explored. [<sup>11</sup>C]Methyl iodide with a specific radioactivity of 412 ± 32 GBq/µmol was obtained in 13 ± 3% decay-corrected radiochemical yield within 6 min via catalytic hydrogenation of [<sup>11</sup>C]carbon dioxide (24 GBq) and subsequent iodination, induced by electron impact. </p><p>Labelled ethyl-, propyl- and butyl iodide was synthesized, within 15 min, via palladium-mediated carbonylation using [<sup>11</sup>C]carbon monoxide. The carbonylation products, labelled carboxylic acids, esters and aldehydes, were reduced to their corresponding alcohols and converted to alkyl iodides. [1-<sup>11</sup>C]Ethyl iodide was obtained via palladium-mediated carbonylation of methyl iodide with a decay-corrected radiochemical yield of 55 ± 5%. [1-<sup>11</sup>C]Propyl iodide and [1-<sup>11</sup>C]butyl iodide were synthesized via the hydroformylation of ethene and propene with decay-corrected radiochemical yields of 58 ± 4% and 34 ± 2%, respectively. [1-<sup>11</sup>C]Ethyl iodide was obtained with a specific radioactivity of 84 GBq/mmol from 10 GBq of [<sup>11</sup>C]carbon monoxide. [1-<sup>11</sup>C]Propyl iodide was synthesized with a specific radioactivity of 270 GBq/mmol from 12 GBq and [1-<sup>11</sup>C]butyl iodide with 146 GBq/mmol from 8 GBq. </p><p>Palladium-mediated hydroxycarbonylation of acetylene was used in the synthesis of [1-<sup>11</sup>C]acrylic acid. The labelled carboxylic acid was converted to its acid chloride and subsequently treated with amine to yield <i>N-</i>[<i>carbonyl</i>-<sup>11</sup>C]benzylacrylamide. In an alternative method, [<i>carbonyl</i>-<sup>11</sup>C]acrylamides were synthesized in decay-corrected radiochemical yields up to 81% via palladium-mediated carbonylative cross-coupling of vinyl halides and amines. Starting from 10 ± 0.5 GBq of [<sup>11</sup>C]carbon monoxide, <i>N-</i>[<i>carbonyl</i>-<sup>11</sup>C]benzylacrylamide was obtained in 4 min with a specific radioactivity of 330 ± 4 GBq/µmol. </p>
| Identifer | oai:union.ndltd.org:UPSALLA/oai:DiVA.org:uu-7171 |
| Date | January 2006 |
| Creators | Eriksson, Jonas |
| Publisher | Uppsala University, Organic Chemistry, Uppsala : Acta Universitatis Upsaliensis |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Doctoral thesis, comprehensive summary, text |
| Relation | Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 ; 227 |
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