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