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