Intra- and inter-molecular catalysis in the iodination of 4-diethylaminobutan-2-one and 5-diethylaminopentan-2-one

Abstract

Measurements are reported of the pK values of 4-diethylaminobutan-2-one and 5-diethylaminopentan-2-one and of their rates of iodination in aqueous buffer solutions at 25 °C. Rates of proton-transfer processes are derived by extrapolating rates of iodination to infinite concentration of tri-iodide ion. Velocity constants are obtained for intramolecular proton transfer to the diethylamino-group, and for intermolecular transfer to ethanolamine and to tris-(2-hydroxyethyl)methylamine. The mechanism of the intramolecular process is discussed, and its efficiency compared with that of similar processes.