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