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