Quinoxalines and Benzimidazoles from Aldoses

In their second communication of 1887, Griess and Harrow3 realized that the reaction of o-phenylenediamine was not so simple as they had assumed in their preliminary note, and that the results differed accord- 

In the presence of acids, continued Griess and Harrow,8 at least two other compounds were formed and could be isolated when a reaction mixture similar to that described in their first paper was allowed to stand for a month in a warm place. The less soluble compound mentioned earlier was named anhydrogluco-o-diaminobenzene. It was formed by the condensation of one molecule of glucose with one molecule of o-phenylenediamine two molecules of water and two hydrogen atoms were eliminated during the reaction. They formulated the product N=CH 

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