Difunctional two-carbon molecules derived from [11C]cyanide

A synthetic strategy for producing new difunctional molecules for potential use as radiolabelling precursors derived from [11C]cyanide is presented. No-carrier-added [11C]CN- was reacted with chloromethyl pivalate to generate the nitrile [11C]cyanomethyl pivalate, 1, which was subsequently converted to ethyl [1-11C]glycolate, 2, with acid and alcohol, or to [1-11C]glycolic acid, 4, using aqueous acid. [1-11C]Ethylene glycol, 3, and [2-11C]2-aminoethanol 5, were obtained by reduction of 2 and 1, respectively, with lithium aluminium hydride. Conditions for obtaining conversions ca. 90% are described. By using a microwave wave-guide cavity to speed up transformations requiring elevated temperatures, all five carbon-11 labelled compounds were synthesized in less than a total of 3 min. (Author)