4-Hydroxy-2-nitro-3-(trifluoromethoxy)pyridine-6-sulfonyl chloride
3-Hydroxy-4-nitro-2-(trifluoromethoxy)pyridine-6-sulfonyl chloride
4-Hydroxy-2-nitro-5-(trifluoromethoxy)pyridine-3-sulfonamide
2-Hydroxy-6-nitro-5-(trifluoromethoxy)pyridine-3-sulfonyl chloride