Rapid synthesis of aliphatic amides by reaction of carboxylic acids, Grignard reagent and amines: application to the preparation of [11C]amides

Abstract

Aliphatic amides have been prepared in moderate to good yields (30–70%) by treatment in THF of magnesium halide carboxylates with amines in the presence of 2.5 equivalents of alkylmagnesium halide. The reaction is rapid (<30 min) and has been successfully applied to the synthesis of amides labelled with carbon-11 (β⁺, t_½: 20.4 min). [¹¹C]Aliphatic amides have been obtained in 15–60% radiochemical yields [decay corrected to end of bombardment (EOB), 5 min amidation reaction time].