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