Aminoacetonitrile (AAN) is the most powerful catalyst for the decarboxylation of acetoacetic acid out of a series of primary amines of widely varying pKa. The rate constants for AAN-catalyzed decarboxylation are closely similar to those for imine formation from AAN and ethyl acetoacetate. Spectrophotometric study of AAN-catalyzed decarboxylation revealed three successive kinetic processes characterized by three pseudo-first-order rate constants. The imine from AAN and acetoacetate could be trapped by cyanoborohydride. Analysis of the kinetics led to rate constants for imine formation and hydrolysis and for interconversion of imine and enamine, as well as for the decarboxylation of the imine. This latter rate constant, 10 sec-1, is 300,000 times faster than that for the decarboxylation of acetoacetic acid itself.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry