Two routes to [11C-carbonyl]organo-isocyanates utilizing [11C]phosgene ([11C]organo-isocyanates from [11C]phosgene)

Two generic radiosynthetic routes for the preparation of [C-11-carbonyl]isocyanates have been developed. Reaction of N-organo-sulfinylamines; RNSO, (R=Me, Et, allyl, cyclohexyl and phenyl) with [C-11]phosgene gave the corresponding [C-11-carbonyl]isocyanates in good radiochemical yield (53-68%) from [C-11]phosgene (decay corrected) in ca 16 min from EOB. Alternatively, the reaction of [C-11]phosgene with N,N'-organo-ureas; (RNH)(2)CO, (R=Me, Et, Pr and phenyl) also gave the corresponding [C-11-carbonyl]isocyanates in moderate radiochemical yield (9-37%) from [C-11]phosgene (decay corrected) in ca 16 min from EOB. For identification, the [C-11-carbozyl]organo-isocyanates were derivatized with 1-(2-methoxyphenyl)piperazine in situ to [C-11-carbonyl]carboxamides and the position of radiolabelling in the carbonyl group confirmed by [C-11/13] co-labeling and subsequent carbon-13 NMR spectroscopy. (C) 2001 Elsevier Science Inc. All rights reserved.