Further Studies on the Bromodecarboxylation Amino Acids with IV-Bromosuccinimide

In a previous publication from this laboratory, a method was described for the quantitative bromodecarboxylation of amino acids, proteins, and peptides (1). A review of decarboxylating compounds and of the theories pertinent to their mode of action has been presented by Schijnberg and Moubacher (2). The reaction of N-bromosuccinimide with various compounds in organic solvents has received considerable investigation and qualitative studies with the reagent in aqueous media (3-8) have been reported. However, the reaction of amino acids with N-bromosuccinimide has received little investigation other than by Barakat et al. (6) and of tyrosine, and tryptophan derivatives and analogues by Witkop et al. (7, 8). Quantitative studies, especially of gas evolution, do not appear to have been carried out although the liberation of bromine and carbon dioxide has been recognized. The experiments reported herein were performed for the purpose of gaining a further understanding of the reaction mechanism involved in the bromodecarboxylation of amino acids with N-bromosuccinimide. Studies were conducted, inter aLa, on the effects of pH, palladium chloride, and concentration of N-bromosuccinimide on the reaction.