Heterocyclic compounds from alloxan and amines. X. Amine purpurates

Abstract

Secondary and tertiary alicyclic amines (piperidine, morpholine, N-ethyl-piperidine, and N-methylmorpholine), and aromatic nitrogen heterocycles (benzimidazole, 2-methyl- and 2-t-butyl-benzimidazole, and pyridine), are shown to yield the heterocyclic amine purpurates (murexide analogues) by reaction with anhydrous alloxan in dry acetic acid. The central nitrogen atom of the purpurate anion, normally derived from ammonia, is considered to arise from degradation of some of the alloxan, and is accompanied by liberation of carbon dioxide. Pyrrolidine did not yield a purpurate (or carbon dioxide) under the reaction conditions.