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