Novel 3,4-diazabenzotropone compounds (2,3-benzodiazepin-5-ones): synthesis, unique reactivity, and biological evaluation.

Efficient synthesis of 3,4-diazabenzo[b]tropone was first achieved utilizing 4π−8π sequential electrocyclic reactions of functionalized benzocyclobutenone derivatives. These compounds are highly electron deficient and readily form amine adducts at ambient temperature. Furthermore, gentle heating resulted in quantitative nitrogen extrusion to produce indenone derivatives. These diazabenzotropones were found to exhibit potent apoptosis-inducing activity against human lymphoma cells. Thus, novel amine-catalyzed nitrogen extrusion reactions and interesting bioactivities were found to be characteristic of these novel diazabenzotropone compounds.