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