5-(Difluoromethyl)-2-fluoro-3-hydroxypyridine-4-sulfonyl chloride
4-(Difluoromethyl)-3-fluoro-5-hydroxypyridine-2-sulfonyl chloride
4-(Difluoromethyl)-3-fluoro-2-hydroxypyridine-5-sulfonyl chloride
4-(Difluoromethyl)-2-fluoro-6-hydroxypyridine-3-sulfonyl chloride