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