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