Late stage iodination of biologically active agents using a one-pot process from aryl amines

A simple and effective one-pot tandem procedure that generates aryl iodides from readily available aryl amines via stable diazonium salts has been developed. The operationally simple procedure and mild conditions allow late-stage iodination of a wide range of aryl compounds bearing various functional groups and substitution patterns. A novel synthetic strategy involving the preparation of nitroaryl compounds followed by a chemoselective tin( ii ) dichloride reduction and the use of the one-pot diazotisation-iodination transformation was also developed. The general applicability of this approach was demonstrated with the preparation of a number of medicinally important compounds including CNS1261, a SPECT imaging agent of the N -methyl- d -aspartate (NMDA) receptor and IBOX, a compound used to detect amyloid plaques in the brain. A tandem process has been developed for the general preparation of aryl iodide compounds from anilines that is also applicable for the late-stage iodination of biologically active agents.