Abstract
For investigation of the structure-activity relationship of xanthine derivatives, two new synthetic routes to 9-deazaxanthines have been found. Catalytical reduction of 6-(2-dimethylaminovinyl)-5-nitrouracils (2), which were prepared by condensation of 5-nitro-6-methyluracils (1) with dimethylformamide (DMF)-diethylacetal or DMF-dimethyl sulfate complex, gave the 2, 4-dioxo-1, 2, 3, 4-tetrahydropyrrolo [3, 2-d] pyrimidines (3) and its 6-dimethylamino relatives (4). Heating 5-formylamino-1, 3, 6-trimethyluracil (15a) also gave pyrrolo [3, 2-d] pyrimidine derivative (3a). Diuretic, cardiac, and central nervous system stimulating activities of the 9-deazaxanthines (3, 6, 9) were weeker than those of caffeine.
