N-p'-Nitrobenzenesulfonyl-p-aminobenzoic Acid (11).-A solution of 3.5 g. of ethyl N-p'- nitrobenzenesulfonyl-p-aminobenzoate (I) in 30 ml. of 95% ethanol and 10 ml. of 10% sodium hydroxide was heated under reflux for 0.5 hour. The alcohol was distilled under ...