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