3-Nitro-6-(trifluoromethoxy)-4-(trifluoromethyl)pyridine-2-carboxylic acid
4-Nitro-3-(trifluoromethoxy)-5-(trifluoromethyl)pyridine-2-carboxylic acid
5-Nitro-2-(trifluoromethoxy)-3-(trifluoromethyl)pyridine-6-carboxylic acid
4-Nitro-5-(trifluoromethoxy)-2-(trifluoromethyl)pyridine-3-carboxylic acid