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