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