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