An efficient protocol for the synthesis of ¹⁴C-labeled 3-pyridineacetate (1) and its N-oxide ([¹⁴C]2) is described.  Oxidation of this pyridine ([¹⁴C]1) to its N-oxide ([¹⁴C]2) proceeded in high yield using H₂O₂ with MeReO₃ as a catalyst.  The reaction employs readily available diethyl [2-¹⁴C]malonate.  This method has proven to be general in preparation of other pyridineacetate derivatives and their N-oxides which have been typically difficult to prepare by other means.  Our development of the Cu(I)Br-coupling methodology as well as application to the synthesis of a ¹⁴C-labeled phosphodiesterase-IV (PDE-IV) inhibitor, [¹⁴C]3, are also reported.