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