1. Synthesis of potential antineoplastic agents. XX. Compounds related to the 3-o-nitrophenylhydrazone of isatin
2. Synthesis of the tumour-inhibitory alkaloids, ellipticine, 9-methoxyellipticine, and related pyrido[4,3-b]carbazoles
3. S. Ruhemann, J. Chem. Soc., 1449 (1910).
4. 6H-indeno[1,2-b]pyrido[3,2-e]pyrazines. A new heterocyclic ring system
5. Compound 3 had a T/C of 98 at 400 mg./kg. against L1210 lymphoid leukemia as reported to us by Drug Research and Development, Chemotherapy, National Cancer Institute. The compound from 3,4-diaminopyridine and ninhydrin was also inactive against L1210 (T/C 97 at 200 mg./kg.) as was the compound from 2,3-diaminonaphthalene and ninhydrin (T/C 97 at 400 mg./kg.). Compound 2 had a T/C of 112 at 25 mg./kg. against L1210 and an ED50 of 1.0 micrograms/ml. against KB cell culture.