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