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