Methyl 3-bromo-5-cyano-6-(difluoromethyl)pyridine-2-carboxylate
Methyl 3-bromo-5-cyano-4-(difluoromethyl)pyridine-2-carboxylate
Methyl 3-bromo-5-cyano-2-(difluoromethyl)pyridine-4-carboxylate
Methyl 3-bromo-4-cyano-6-(difluoromethyl)pyridine-2-carboxylate