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