5-Amino-4-(difluoromethyl)-3-hydroxypyridine-2-carboxylic acid
3-Amino-4-(difluoromethyl)-5-hydroxypyridine-2-carboxylic acid
3-Amino-4-(difluoromethyl)-2-hydroxypyridine-6-carboxylic acid
3-Amino-4-(difluoromethyl)-2-hydroxypyridine-5-carboxylic acid