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