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