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