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