Investigation of the Reactions of Indole-2,3-diones with Biuret: A Novel Approach for the Synthesis of Spiro[indole-triazines]

Reactions of indole-2,3-diones with biuret afforded 1,3-dihydro-3-ureidoformimido-2H-indol-2-ones and spiro[3H-indole-3,2′(1′H)-(1,3,5)triazine]-2,4′,6′(1H,3′H,5′H)-triones indicated these to be solvent dependent. The chemical structures of the products were elucidated by their comprehensive spectroscopic (IR, 1H-NMR, 13C-NMR, 19F-NMR, and Mass) as well as analytical analysis.