3-Methoxy-2-nitro-6-(trifluoromethoxy)pyridine-5-carboxylic acid
3-Methoxy-2-nitro-5-(trifluoromethoxy)pyridine-4-carboxylic acid
6-Methoxy-2-nitro-3-(trifluoromethoxy)pyridine-4-carboxylic acid
2-Methoxy-6-nitro-4-(trifluoromethoxy)pyridine-3-carboxylic acid