Isocyanate intermediates. II. Trichloromethyl chloroformate - A convenient reagent for the Preparation of Diisocyanates with benzene or furan rings

One‐pot synthesis of [11C]ureas via triphenylphosphinimines

“…6,8,10 Synthetic routes to isocyanates and ureas with phosgene substitutes have also been described. Trichloromethyl chloroformate (diphosgene) 11 was one of the first substitutes affording certain unlabeled isocyanates in excellent yields. Carbon dioxide has also been used in methods that avoid the preparation of phosgene, for example, [ 11 19,20 and selenium-mediated syntheses of 11 C-carbamoyl compounds.…”

“…[ 11 C]CO 2 , [ 11 C]CH 4 ) or those rapidly prepared from them (e.g. increased, there is a need for new and simple methodologies that give access to 11 C-labeled pharmaceuticals in short synthesis times and in high yields. Preferably, these general methodologies are suitable for automation.…”

“…The demand for new radiolabeling methods is growing with the increasing use of PET throughout drug development processes and medical imaging. The radioisotope 11 C is very valuable for this purpose, since it permits the radiosynthesis of the native compound. However, one has to take into account that there is a relative limited number of labeled synthons (e.g.…”

“…[2][3][4][5] So far, 11 C labeling of ureas in the carbonyl function has been performed mainly starting from [ 11 C]phosgene. In this paper, an efficient synthesis of [ 11 C]ureas via triphenylphosphinimines and [ 11 C]CO 2 is described.…”

Radiosynthesis of [11C]docetaxel

“…reaction of the primary amine of docetaxel (10) 29 with the 11 C isotope in the carbonyl function, would require the use of either [ 11 C]phosgene again or an alternative with the consequence that the 11 C isotope has to be introduced in an (too) early stage of the synthesis route (time limit).…”