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

A series of C-11-labeled ureas was prepared using a rapid and efficient one-pot procedure. First, the intermediate [C-11]phenylisocyanate was formed with phenyl-triphenylphosphinimine and [C-11]CO2. A range of amines was then reacted with the [C-11]phenylisocyanate yielding the [C-11]urea derivatives in short synthesis times. This easy-to-handle method circumvents disadvantages of known procedures and generates the possibility to prepare other kinds of C-11-labeled compounds using a variety of phenylphosphinimines in combination with different nucleophiles. The presented approach is an alternative to the use of established methods in C-11-labeling chemistry. Copyright (c) 2006 John Wiley & Sons, Ltd.