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