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