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