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