An on-line synthesis of “no-carrier-added” [11C]phosgene

Dikšić, Mirko; Jolly, Dean; Farrokhzad, Simin

doi:10.1016/0047-0740(82)90089-4

Cited by 20 publications

(9 citation statements)

References 4 publications

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“…In the first case, [ 11 C]CO was passed through a quartz tube coiled around a strong UV lamp while chlorine gas was mixed in to concentrations of 15–50%. 96,97 [ 11 C]COCl 2 was produced in up to 90% radiochemical yields (decay-corrected) and easily separated from Cl 2 by passing the mixture through antimony or amalgamated copper. The second method was a non-photochemical one, producing [ 11 C]COCl 2 in 30–50% RCY.…”

Section: Radiochemistry With [11c]cocl2mentioning

confidence: 99%

¹¹CO bonds made easily for positron emission tomography radiopharmaceuticals

et al. 2016

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The positron-emitting radionuclide carbon-11 (11C, t1/2 = 20.3 minutes) possesses the unique potential for radiolabeling of any biological, naturally occurring, or synthetic organic molecule for in vivo positron emission tomography (PET) imaging. Carbon-11 is most often incorporated into small molecules by methylation of alcohol, thiol, amine or carboxylic acid precursors using [11C]methyl iodide or [11C]methyl triflate (generated from [11C]CO2). Consequently, small molecules that lack an easily substituted 11C-methyl group are often considered to have non-obvious strategies for radiolabeling and require a more customized approach. [11C]Carbon dioxide, [11C]carbon monoxide, [11C]cyanide, and [11C]phosgene represent alternative carbon-11 reactants to enable 11C-carbonylation. Methodologies developed for preparation of 11C-carbonyl groups have had a tremendous impact on the development of novel PET radiopharmaceuticals and provided key tools for clinical research. 11C-Carbonyl radiopharmaceuticals based on labeled carboxylic acids, amides, carbamates, and ureas now account for a substantial number of important imaging agents that have seen translation to higher species and clinical research of previously inaccessible targets, which is a testament to the creativity, utility, and practicality of the underlying radiochemistry.

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Section: Radiochemistry With [11c]cocl2mentioning

confidence: 99%

¹¹CO bonds made easily for positron emission tomography radiopharmaceuticals

et al. 2016

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“…11 The specific activity of our nC-labeled estrogens is limited by the specific activity of the [nC]phosgene, which in turn appears to depend mainly on the purity of the chlorine gas used to react with the UC0. 18 The latter is formed with a high specific activity of at least 104Ci/ mmol, which decreases almost 103-fold to 40 Ci/mmol upon formation of the [nC]phosgene.18 Thus, higher specific activities of our nC-labeled estrogens can only be achieved by more stringent control of carrier introduction during [nC]phosgene formation. Since the present specific activities and radiochemical yields were sufficient for in vivo uterine uptake studies, no effort was made to improve these values at this time.…”

Section: Discussionmentioning

confidence: 99%

“…reaction on nitrogen and processed to [nC]phosgene by reacting nCO with chlorine gas in a quartz tube facing a 275-W CGE suntanner bulb. 18 The thin-layer chromatography (TLC) was conducted on 0.25-mm thick Brinkman silica gel 60 F-254 plates.…”

Section: Discussionmentioning

confidence: 99%

“…The [nC]phosgene was prepared at a modest specific activity of about 40 Ci/mmol by the UV-induced reaction of uCO with Cl2. 18 The unlabeled products were identified by °Organ uptake (percent of injected dose per gram, normalized for animals of 100 g) 10 min after injection of the uC-labeled derivatives of estradiol ([nC]2) and hexestrol (["C]7) in the presence or absence of coinjected estradiol (mean plus or minus standard deviation for five rats). Comparison between estradiol-treated animals and untreated animals by means of the Student's t test for matched pairs revealed no significant difference in the "C distribution pattern for 2 or 7.…”

Section: Scheme Imentioning

confidence: 99%

See 1 more Smart Citation

Synthesis, receptor binding, and target-tissue uptake of carbon-11 labeled carbamate derivatives of estradiol and hexestrol

Ouellet¹,

Rousseau²,

Brasseur³

et al. 1984

J. Med. Chem.

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The reaction of ethyl chloroformate with amino compounds has been evaluated as a simple route to carbon-11 labeling of steroid hormone-receptor-based imaging agents. Both a 17 beta-amino analogue of estradiol and an aminoethyl derivative of the nonsteroidal estrogen hexestrol with potential affinity for the estrogen receptor were studied. The unlabeled carbamate derivatives of the amino estrogens were prepared by standard methods, and the 11C-labeled analogues were synthesized from [11C]ethyl chloroformate, generated by purging ethanol with [11C]phosgene. Both carbamates showed weak in vitro binding affinity for the estrogen receptor, and only the 11C-labeled hexestrol exhibited a small but significant estrogen-responsive uterus uptake in immature rats.

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“…Many of these gases, e.g. nc-labelled nitrosoureas [38,39] using 11@ phosgene [40] could be prepared in an on-line mode, allowing us to do an on-line synthesis. A radionuclide requiring special attention during production and use is fluorine-18.…”

Section: Radionuclide Productionmentioning

confidence: 99%