5H-[1,2,5]selenadiazolo[3,4-f]indole as a masked form of 5,6-diaminoindole

6-Nitroindoline (9) was converted into 1-acetyl-5,6-aminoindoline (12) which was then transformed via selenadiazoles (13-15) to the title selenadiazoloindole (4) by two alternative 3-step synthetic sequences in 38-.42% overall yield from 12. The unstable 5,6-diaminoindole (16) was then obtained by reductive deselenation of 4. Fully assigned H-1, C-13 and Se-17 NMR spectral data for the title indole (4) and Se-77 NMR spectral data for the intermediate selenadiazoles (13-15) are presented.