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