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