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