Polymerization Reactions occurring during Dinitrophenylation of α-, β- and ω-Amino-acids with Sanger's Reagent

Abstract

NUMEROUS papers have been published concerning the identification and determination of amino-acids by the dinitrophenylation method introduced by Sanger¹. We are not aware, however, of any indications in the literature about the occurrence of polymerization reactions during dinitrophenylation. In an attempt to work out a procedure for the quantitative determination of minute amounts of ɛ-amino-caproic acid and its linear oligomers, we have found that such polymerization reactions do occur. Similar results have been found during dinitrophenylation of other ω-amino-acids and of glycine and β-alanine. Since these side-reactions may lead to complications in investigations on the separation and determination of dinitrophenyl amino-acids in general, it seems useful to communicate these facts briefly.