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