Dilactams. Synthesis of nonsymmetrical dibenzodiazocinediones

We report the first examples of nonsymmetrical dibenzodiazocinediones, mono-, di-, tri- and tetra-substituted in the aromatic rings including a benzo pyridino diazocine, by a new short method without the requirement of protection. The procedure involves conversion of an anthranilic acid to its sulfinamide lactone followed by direct heating with a different N-alkylanthranilic acid.