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