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