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