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