Quinoxalines derived from disaccharides with O-phenylenediamine under weakly acidic reflux conditions.

Abstract

Quinoxaline derivatives from disaccharides (isomaltose, maltose, laminaribiose, trehalose and sucrose) and o-phenylenediamine (OPD) under weakly acidic reflux conditions were subjected to GLC and GC-MS analyses.Three high-molecular-weight quinoxaline derivatives (IA-I, -II and -III) were obtained from isomaltose in a yield of 90%, indicating no splitting of the glucosidic linkages. Both low- and high-molecular-weight quinoxaline derivatives were obtained from 5 mm maltose. From 50 mm maltose, a low-molecular-weight quinoxaline, GA-I, was obtained predominantly. Quinoxalines from laminaribiose were both high (LA-I and -II) and low (ATBQ, GA-I, G-l and GA-II) molecular-weight derivatives, in yields of 18% and 48%, respectively. LA-I and -II were stereoisomers, at the C-3 position, of laminaribiose. Trehalose gave no quinoxalines, and sucrose gave only small amounts of low-molecular-weight quinoxalines.From these results, we found that 1,6-linkages of the disaccharides used are most resistant to the OPD degr...