Ethyl 3-bromo-4-(difluoromethyl)-6-nitropyridine-2-carboxylate
Ethyl 3-bromo-4-(difluoromethyl)-5-nitropyridine-2-carboxylate
Ethyl 3-bromo-4-(difluoromethyl)-2-nitropyridine-5-carboxylate
Ethyl 3-bromo-2-(difluoromethyl)-6-nitropyridine-4-carboxylate