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