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