Ethyl 5-(difluoromethyl)-2-methoxy-4-nitropyridine-3-acetate
Methyl 3-(difluoromethyl)-5-methyl-6-nitropyridine-2-carboxylate
Ethyl 5-(difluoromethyl)-2-methoxy-3-nitropyridine-4-acetate
Methyl 3-(difluoromethyl)-5-methyl-4-nitropyridine-2-carboxylate