Kinetics of the Decarboxylation of Acetoacetic acid

Abstract

The decarboxylation of acetoacetic acid CH₃COCH₂CO₂H → CH₃COCH₃+CO₂ and its anion have been studied in aqueous solution over a range of temperature. Although the acid decomposes approximately 50 times faster than the anion at 37°, the activation energy of the acid (23.7 kcal mole^-1) is comparable with that of the anion (22.9 kcal mole_-1) and the large difference in reactivity is due to an entropy effect. The significance of these results is discussed and a comparison made with other β-keto acid decarboxylations.