4-Cyano-6-hydroxy-3-(trifluoromethoxy)pyridine-2-sulfonyl chloride
4-Cyano-2-hydroxy-3-(trifluoromethoxy)pyridine-5-sulfonyl chloride
5-Cyano-3-hydroxy-4-(trifluoromethoxy)pyridine-2-sulfonyl chloride
3-Cyano-5-hydroxy-2-(trifluoromethoxy)pyridine-4-sulfonyl chloride