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