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