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