Synthesis of 14C-labelled butoxyethoxyethanol

Butoxyethoxyethanol1, an organic solvent used as carrier in the levamisole pour-on formulation, was synthesized via a Makosza etherification of 1-14C- labelled bromobutane with mono tetrahydropyranyl (T.H.P.) protected diethylene glycol and subsequent removal of the T.H.P. protecting group. The compounds' synthetic yield was 88.8 %; it had a specific activity of 32.5 mci/mmol. The reaction product was radiochemically pure (99.6 %) according to high-performance liquid chromatography and thin-layer chromatography in three solvent systems.