Cyclization of 2-arylamino-1,4-naphthoquinones to benzo[b]phenazine-6,11-dione 5-oxides

A method for the synthesis of a new group of tetracyclic diazaquinones, viz., benzo[b]-phenazine-6,11-dione 5-oxides, was developed and the pathways of their further modifications were outlined.