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