The first synthesis of fluorine-containing indeno[2,1c][1,2,6]-selenadiazines

4-Trifluoromethyl-4a-chloro-5,6,7,8,9,9-hexafluoro(4aH,9H)indeno[2,1c][1,2,6]-selenadiazine (1) has been synthesised by the interaction of 2-amino-3-(1-imino-2,2,2-trifluoroethyl)hexafluoroindene (2) with SeCl4 in the presence of HCl acceptors. Hydrolysis and reaction with CF3SO3H are also described. Arrangement of atoms for 1 are provided.