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