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