A new indolopyrrolocarbazole antitumor substance, ED-110, a derivative of BE-13793C.

^TV-dimethylformamide (DMF, 37 ml) was added potassium carbonate (510mg, 3.69mmol) and benzyl bromide (170^1, 1.43mmol) at room temperature (r.t.). The mixture was stirred at r.t. for 2hours and extracted with ethyl acetate (200ml) after the addition of water (200 ml). The ethyl acetate layer was concentrated under reduced pressure and the residue was chromatographedon silica gel to obtain 1,1l-dibenzyloxy-12,13-dihydro-5//indolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7(6//)-