Improved Syntheses of Halogenated Benzene-1,2,3,4-Tetracarboxylic Diimides.

The preparation of halogenated benzene-1,2,3,4-tetracarboxylic diimide derivatives is challenging because of the possibility of competitive incorrect cyclizations and S N Ar reactivity. Here, we demonstrate that bypassing traditional cyclic anhydrides and instead directly reacting dihalobenzene-1,2,3,4-tetracarboxylic acids with primary amines in acetic acid solvent successfully provides a range of desirable ortho -diimide products in good yields. Furthermore, we demonstrate that sterically challenging N -derivatizations can be readily achieved under microwave reactor conditions. The halogenated diimides described here are attractive building blocks for organic materials chemistry.