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