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