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