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