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