Acid-base equilibria and decomposition of secondary (N-Cl)-α-amino acids

• Published in: Tetrahedron Vol. 50; no. 35; pp. 10509 - 10520
• Main Authors: Armesto, X.L., Canle, M.L., Gamper, A.M., Losada, M., Santaballa, J.A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1994; Elsevier
• Subjects: Chemistry; Exact sciences and technology; Kinetics and mechanisms; Organic chemistry; Reactivity and mechanisms; Acid base balance; Equilibrium constant; Reaction mechanism; Chemical decomposition; Kinetic parameter; Rate constant; Acid medium
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/S0040-4020(01)89591-0

The decomposition of (N-Cl)-Sarcosine, (N-Cl),(N-Me)-Alanine, (N-Cl)-Proline, (N-CI),(N-Me)-Valine, and (N-Cl)-2-piperidine carboxylic acid (Pipecolic acid) was studied under acid conditions. The results suggest the participation of the four possible species of the (N-Cl)-α-amino acid. A reaction mechanism is proposed which allows us to estimate the rate constant for the decomposition of each species, as well as the yet unknown macroscopic, microscopic and tautomeric equilibrum constants. The relation between the different rate and equilibrium constants is also analyzed. The rate constants for the decomposition of secondary (N-Cl)-α-amino acids in acid medium, as well as their macroscopic, microscopic and tautomeric equilibrium constants have been obtained.