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