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