In alkaline pH at 40° succinimide simultaneously hydrolyzes to form succinamic acid and reacts with NH2OH to form N‐hydroxysuccinamide which undergoes ring closure to form N‐hydroxysuccinimide. At pH 9.5 N‐hydroxysuccinimide is the major product from hydroxyaminolysis of succinimide at 40°. At pH 12, N‐hydroxysuccinimide undergoes further hydrolysis to form N‐hydroxysuccinamic acid. Pseudo first‐order rate constants for the loss of succinimide as a function of pH and NH2OH concentration were established by colorimetric determination of the hydroxamic acid‐iron complex or UV spectrophotometric determination of the N‐hydroxysuccinimide. Reaction conditions favoring N‐hydroxysuccinimide formation were employed to develop a new UV assay for succinimide. This assay is six times more sensitive than the assay based on formation of the hydroxamic acid with subsequent colorimetric determination of its iron complex. Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company
