Prebiotic adenine synthesis from HCN—Evidence for a newly discovered major pathway

Three new imidazole derivatives have been isolated and characterized from oligomerizing HCN solutions. On the basis of these results as well as the earlier identification of a new precursor to adenine, a new and major pathway leading to the formation of adenine is suggested. The route accounts for the synthesis of adenine-8-carboxamide from cis-diamino-maleonitrile, without requiring an isomerization to the trans configuration or reactions with formamidine. The formation of previously reported imidazoles is also explained.