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