5-Cyano-2-nitro-3-(trifluoromethoxy)pyridine-4-carboxylic acid
3-Cyano-2-(difluoromethyl)-5-(trifluoromethoxy)pyridine-4-acetic acid
4-Cyano-5-nitro-3-(trifluoromethoxy)pyridine-2-carboxylic acid
6-Cyano-2-(difluoromethyl)-3-(trifluoromethoxy)pyridine-4-acetic acid