Syntheses, antitumor activity and vascular relaxing effet of purino(7,8-g)-6-azapteridines and (1,2,4)triazino(3,2-f)purines.

Abstract

Novel heterocycles, purino [7, 8-g] -6-azapteridines and [1, 2, 4] triazino [3, 2-f] purines, were synthesized and their biological activities were examined. Heating of 7, 8-diamino-1, 3-dimethylxanthine (2), which was obtained by the reaction of 8-aminotheophylline with hydroxylamine-Ο-sulfonic acid, with hydrochloric acid gave 2, 4, 7, 9-tetramethylpurino [7, 8-g] -6-azapteridine-1, 3, 8, 10 (2H, 4H, 7H, 9H) -tetrone (4) in 96% yield; this product was identical with the compound obtained by the reaction of 2 with alloxan followed by methylation. Treatment of 4 with alkylamines gave 3-alkylamino-2-alkylcarbamoyl-6, 8-dimethyl [1, 2, 4] triazino [3, 2-f] purine-7, 8 (6H, 8H) -diones (10a-g) in 63-95% yields. Compound 4 was active against P 388 leukemia. Vascular relaxing effects of some of the triazino [3, 2-f] purines (10a, b, e, f) were examined, but none showed potent activity.