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