4-(Difluoromethyl)-5-nitro-3-(trifluoromethyl)pyridine-2-acetic acid
2-(Difluoromethyl)-4-nitro-3-(trifluoromethyl)pyridine-5-acetic acid
2-(Difluoromethyl)-3-nitro-6-(trifluoromethyl)pyridine-4-acetic acid
4-(Difluoromethyl)-3-nitro-2-(trifluoromethyl)pyridine-6-acetic acid