Tetracarboxylic Bisimide–Lactam Ring Contraction: A Novel Type of Rearrangement

Abstract

A novel type of rearrangement occurs when aromatic bisimides that are usually chemically inert are treated with alkali metal hydroxides in alcohols. With this reaction naphthalene-lactamimides, some with high fluorescent quantum yields and large Stokes-shifts, can be obtained in a single step [Eq. (a); R = aryl].