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