Abstract The first synthesis of benzo [1, 2-c: 3, 4-c'] bis [1, 2, 5] selenadiazole has been developed starting from commercially available 4-nitrobenzo-2, 1, 3-selenadiazole. Improved syntheses of the related heterocycles [1, 2, 5] selenadiazolo [3, 4-e]-2, 1, 3- benzothiadiazole, furazanobenzo-2, 1, 3-thiadiazole and furazanobenzo-2, 1, 3- selenadiazole are also reported.