First synthesis of 6,7-diaminoindole and 1,2,5-selenadiazolo[3,4-g]indole

Abstract

5-Methyl-4-nitro-2,1,3-benzoselenadiazole (1) was converted into 1,2,5-selenadiazolo[3,4-g]indole (3) by the Batcho-Leimgruber indole synthesis. Subsequent deselenation afforded 6,7-diaminoindole (4) which on treatment with biacetyl afforded 2,3-dimethylpyrrolo[2,3-f]quinoxaline (5) in 80% yield from 3.