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