Ethyl 3-cyano-5-nitro-4-(trifluoromethoxy)pyridine-2-carboxylate
Ethyl 3-cyano-2-nitro-6-(trifluoromethoxy)pyridine-5-carboxylate
Ethyl 2-cyano-5-nitro-4-(trifluoromethoxy)pyridine-3-carboxylate
Ethyl 6-cyano-4-nitro-2-(trifluoromethoxy)pyridine-3-carboxylate