N-Acetyl-N-acetoxy-4-chlorobenzenesulfonamide is a pro-drug of the potent vasorelaxant nitroxyl, H-N=O, which it slowly releases in neutral solution. HNO eventually dimerizes and dehydrates to N2O, without producing NO. N-Acetyl-N-acetoxy-4-chlorobenzenesulfonamide is also a powerful inhibitor of ALDH(aldehyde dehydrogenase).