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