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