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