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