Divergent synthesis of organophosphate [C]VX- and [C]Sarin-surrogates from a common set of starting materials.

Radiolabeled 1-[C]ethyl, 4-nitrophenyl methylphosphonate (VX surrogate) and 2-[C]-propanyl, 4-nitrophenyl methylphosphonate (sarin surrogate) were developed as organophosphate (OP) tracers. The [C]ethyl- and [C]isopropyl-iodide radiolabeled synthons were obtained by temperature controlled, in loop reactions of [C]CO with MeMgBr followed by reduction with LiAlH, then reaction with HI. Distillation of the [C]alkyl iodides into a solution of hydrogen (4-nitrophenyl)methylphosphonate and cesium carbonate afforded the desired tracers in >95% radiochemical purity, yields from [C]CO of 1-3% and 1.7-15.1 GBq/mmol molar activities.