Abstract
6-Benzylidenehydrazino-3-methyluracils were treated with sodium nitrite in acetic acid to give the corresponding 5-nitrosouracils. Dehydrative cyclization of the 5-nitrosouracils with acetic anhydride afforded 6-substituted 3-methyl-7-azalumazines, ethylation of which gave 6-substituted 1-ethyl-3-methyl-7-azalumazines. Treatment of these 7-azalumazines thus obtained and 6-substituted 1, 3-dimethyl-7-azalumazines with alcoholic sodium hydroxide caused a benzilic acid type rearrangement followed by decarboxylation and oxidation by air to give the respective 5H-imidazo [4, 5-e]-as-triazine-6 (7H)-ones (6-azapurines). Prolonged hydrolysis of 3-substituted 7-ethyl-5-methyl-5H-imidazo [4, 5-e]-as-triazine-6 (7H)-ones with alcoholic sodium hydroxide caused the ring cleavage to give 3-substituted 6-ethylamino-5-methylamino-as-triazines, which were fused with benzamidine hydrochloride to give rise to 3-substituted 7-ethyl-6-phenylimidazo [4, 5-e]-as-triazines.
