4-(Difluoromethyl)-3-nitro-6-(trifluoromethoxy)pyridine-2-carboxylic acid
4-Methoxy-3-(trifluoromethoxy)-5-(trifluoromethyl)pyridine-2-acetic acid
4-(Difluoromethyl)-3-nitro-2-(trifluoromethoxy)pyridine-6-carboxylic acid
6-(Difluoromethyl)-3-methoxy-4-(trifluoromethoxy)pyridine-2-carboxylic acid