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