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