A. Da Settimo et al., Synthesis of a novel purine-containing heterocyclic ring system: 8,10-dimethylindolo[2 ',3 ': 5,6][1,2,4]triazino[4,3-f]purine-9,11(8H,10H,13H)-dione, J HETERO CH, 37(2), 2000, pp. 373-377
The preparation of a novel purine containing heterocyclic ring system, indo
lotriazinopurine, by the condensation of 8-hydrazinotheophylline with 5-sub
stituted isatins via the intermediate hemiaminal and hydrazone derivatives,
is described.