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