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