4-Chloro-3-cyano-6-(trifluoromethoxy)pyridine-2-carboxylic acid
3-Cyano-4-hydroxy-5-(trifluoromethoxy)pyridine-2-carboxylic acid
4-Chloro-3-cyano-2-(trifluoromethoxy)pyridine-6-carboxylic acid
3-Cyano-2-hydroxy-5-(trifluoromethoxy)pyridine-4-carboxylic acid