6-Azapurines (imidazo[4,5-e]-as-triazines)
Abstract
Treatment of 3-substituted 7-amino-5-hydroxy-primido[5,4-e]-as-triazine 4-oxides (IIIa—d) with acetic anhydride or alcoholic sodium hydroxide caused a benzylic acid-type rearrangement followed by decarboxylation and dehydration to give the corresponding 6-acetylaminoimidazo[4,5-e]-as-triazines (IVa—d) or 3-aminoimidazo[4,5-e]-as-triazines (Va—c); similarly, 3-substituted toxoflavin 4-oxides (VIa—c) gave the respective 1,5-dimethyl-1H-imidazo[4,5-e]-as-triazin-6-(5H)-ones (VIIa—c), and 3-substituted fervenulin 4-oxides (VIIIa—c) gave the respective 5,7-dimethyl-5H-imidazo[4,5-e]-as-triazin-6(7H)- ones (IXa—c).