THE FACILE SYNTHESIS OF 6-AZAPURINES BY TRANSFORMATION OF TOXOFLAVINS (7-AZAPTERIDINES)

This paper describes a reliable and facile synthesis of 6-azapurines (1,5-dimethyl-1H-imidazo[4,5-e][1,2,4]triazin-6(5H)-ones) by treatment of toxoflavins (7-azapteridines) with 10% aqueous sodium hydroxide at 5-25 degrees C along with a benzilic acid type rearrangement, followed by decarboxylation and oxidation by air. Furthermore, heating the 6-azapurines in 10% ethanolic sodium hydroxides afforded the corresponding 1,2,4-triazine-5,6(1H,4H)-diones to be caused by ring fission of the imidazole of 6-azapurines.