On the preparation of 1,2,5-selenadiazolo [3,4-e]indole and its [3,4-f] and [3,4-g] isomers through the Batcho-Leimgruber indole synthesis

1,2,5-Selenadiazolo[3,4-e]indole 6 was prepared by applying the Batcho-Leim gruber indole synthesis on 4-methyl-5-nitro-2,1,3-benzoselenadiazole 9. Thi s methodology was unsuccessful when applied to 5-methyl-6-nitro-2,1,3-benzo selenadiazole 14 for the synthesis of 1,2,5-selenadiazolo[3,4-f]indole 5. A n improvement on the preparation of 1,2,5-selenadiazolo[3,4-g]indole 3 is r eported. An initial study on the bromination of 3 and the Se-77-NMR chemica l shifts of 3 and 6, and of their precursors are presented.