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