2-Hydroxy-3-nitro-6-(trifluoromethoxy)pyridine-5-carboxylic acid
2-Hydroxy-3-nitro-5-(trifluoromethoxy)pyridine-4-carboxylic acid
3-(Difluoromethyl)-5-hydroxy-2-(trifluoromethoxy)-4-(trifluoromethyl)pyridine
5-(Difluoromethyl)-4-hydroxy-3-(trifluoromethoxy)-2-(trifluoromethyl)pyridine