2-Cyano-6-(difluoromethyl)-3-nitro-4-(trifluoromethoxy)pyridine
4-Cyano-3-(fluoromethyl)-6-nitro-2-(trifluoromethoxy)pyridine
4-Cyano-2-(fluoromethyl)-6-nitro-3-(trifluoromethoxy)pyridine
6-Cyano-3-(difluoromethyl)-4-nitro-2-(trifluoromethoxy)pyridine